Girlfriend Wears My Sister's Panties

I rode the subway home from work in a minor frenzy... It was Friday afternoon at 5:00. The workweek was finally over, and my girlfriend and I had the apartment to ourselves all weekend. Elise and I shared a room in a two-bedroom apartment on the Upper West Side of New York City. It was a great location, and our roommate actually wasn't that bad: she was my sister.

My sister, Chelsea, and my girlfriend, Elise, had been best friends since high school, and my sister had actually set Elise and I up on our first date. It worked out very nicely that my sister's best friend became my girlfriend. We got along great as a threesome, and when we all moved to NYC the living situation was easy to sort out.

The main hallway of the apartment led straight down to a dead end with two doors: our bedroom on the left, and Chelsea's bedroom on the right. It shared a common wall, which was perhaps the only difficult thing about the setup. The rooms weren't exactly soundproof, so privacy was slightly limited. Apparently Chelsea had complained to Elise once about overhearing us having sex, and since then we'd kept it on the quiet side.

But this weekend my sister was upstate, and we had the apartment all to ourselves. Elise and I had been whispering for days about the privacy we would have starting Friday after work, and we had vowed to get frisky as soon as Chelsea was gone. My hope was the Elise would beat me home and be ready and waiting...

Fortune really favored me, and when I walked in the apartment door I found that's exactly what had happened. The lights were low in the living room, some nice music was coming from the bedroom, and when I paused for a moment in the hallway I heard Elise's voice call, "Nick... I'm waiting in the bedroom for you..."

I jogged down the hall, kicking my shoes off, and took a left at the end into our bedroom. The lights were low here as well, and there stood Elise in her lace-clad glory.

Elise knew one of my absolute turn-ons is a girl in sexy panties. I devour that image... I feel like a girl in a panty set can look so much sexier than a fully naked one. She had a huge collection of satin, lace, and cotton (mostly gifts from me) and if she's feeling particularly playful when we have sex she'll slip into an outfit that she knows gets me rock hard.

My pleasant surprise was to find her standing there in a brand new bra and panty set I had never seen! It was extremely minimalistic, and mostly lace. The pattern was a deep green frilly lace with purple accents running through it. The waistband and flowers were purple and it clung to Elise ever so lightly, as if it were a size or two big for her.

It was then I noticed the truth: it was a peek-a-boo panty set.

For the uninitiated, a peek-a-boo panty set has delightful little openings over both tits, and right up the middle when you head downtown. They do the job to cover some flesh, but get right down to it and some lewd visuals can be had. It's like a step beyond nudity, putting on lingerie specifically so you can see all the naughty bits. Puffy areolas pointing through delicate lace, full pussy lips pouting out between the bottom slit... I tip my hat to the mind that thought these things up.

Elise had never worn a full peek-a-boo set in bed before. Sure, we'd dabbled with certain crotchless panties before, but this was the real deal. I looked at her and knew I'd soon be fucking her through these panties.

I stepped closer, shrugging out of my suit jacket and unbuckling my pants. "Fuck, Elise," I said, "You look amazing in that outfit."

"Really?" she asked. "I was hoping you'd like it..." She gave me a little Cheshire cat grin, having known full well I'd love this little ensemble. I finally removed my shirt and stepped to her, now wearing only my boxer briefs. "I knew Chelsea would be gone this weekend, and I wanted to wear something for you that I knew would make you moan for me."

I rewarded her with a light moan in her ear as I used my body to push her gently to the bed, caressing her neck with my nose and working my way down her neck. She moaned in turn and arched her back in pleasure. This worked perfectly in my favor, as it forced her small breasts up against the material of the bra, finally allowing them to fill it out. Her tiny, pert nipples jutted out between the lacy fabric, two lines of purple embellishment framing them well.

I had to have my fill of what I'd just seen, so my kisses continued their way down her sternum until my nose was pressed into the wonderful fabric of her bra. One of my immediate thoughts was, "Huh, this doesn't exactly feel brand new." It wasn't as soft as most brand new lingerie was, and it certainly didn't have that new-from-the-store smell to it. It was definitely perfumed slightly, but it was more familiar than just a random store brand.

This passed through my mind in an instant, and it was nearly forgotten when I got my lips around Elise's exposed nipple. She moaned and grabbed the back of my hair with both hands, feeding her breast to me right through the fabric of her bra. I nuzzled my face into her chest, devouring her and loving the surprise she had presented me with for this special Friday night.

I looked up and kissed her hard on the mouth, controlling her lips and tongue with mine and letting her know she'd hit the jackpot for pleasing me. I backed off and asked, "These things are perfect. Where did you get them?"

I expected the usual suspects, Victoria's Secret, Senza, or some other brand. But just as I moved my lips back to Elise's tits I heard. "Well... I wasn't sure if you'd mind, and I hope you don't, but they're actually Chelsea's."

I paused, my mouth half an inch away from my girlfriend's tit and the lace that covered it. Chelsea's. These panties and this bra belonged to my sister.

Weird.

I was processing this rapid-fire, as my full body was completely focused on the nearly nude form in my hands. But for some reason it did not compute. I mean, I know I had the thoughts, "So that's why they fit a little big. Chelsea is slightly curvier than Elise with slightly larger breasts. My girlfriend doesn't fill out the bra quite as much as my sister." I also had the thought, "Well, that explains why I recognize the perfume smell, this lingerie lives in a drawer with my sister's other lingerie and probably her perfume. This is what all of my sister's lingerie smells like."

Now despite these thoughts, there was no effect. It was as if my hard dick and the beautiful vixen in front of me were blocking the receptors to my brain that should have made me said to my girlfriend, "Um, ok, that's a little weird. Maybe take them off." No, I certainly didn't say that. After breaking from my momentary reverie I looked up in my girlfriend's eyes and said nonchalantly, "Of course I don't care. I don't care where they came from, I just know you look fucking good in them."

Elise smiled with relief and approval and rewarded me by pulling the palm of my hand onto her mound. My arousal instantly spiked. I felt my girlfriend's plush pussy bulge into my hand through the lace material. It was a wonderful mixture of skin and lace as her labia bulged out between the open slit, pushing those purple seams apart. We kissed deeply again, my middle finger delving deep, deep into Elise's cunt. She was so wet my entire digit was immediately encased in the slick, pillowy warmth of her pussy. I kept my whole palm on her mound, pushing and forcing my middle finger up into her firmly with each stroke.

We kissed passionately, our tongues swirling over one another, and Elise reached down and grabbed my dick through my boxer briefs. It felt so good to finally have her little hand on me, stroking me stiffer and stiffer. I brought my left hand up to Elise's breast and began to knead it through the soft material. It was the perfect size in my hand. I felt her nipple catch my finger and I was reminded of my access, so I bent my head back to Elise's breast. I clutched onto the little pearl of her nipple as I sucked gently, feeling a bit of the lacy bra against my lips as well. I love sucking Elise's tits. And I WAS sucking Elise's tits.

I was sucking Elise's tits through Chelsea's bra.

I was sucking Elise's tits through my sister's bra.

That was a weird thought.

I probably lost my stride for only half a second, but then I continued sucking away... with new thoughts coursing through my head.

As Elise continued massaging up and down the length of my dick I continued kneading and sucking her breasts. "My lips and tongue are literally licking and sucking the same spots that my sister's tits get sucked. My sister's nipples have poked right through this very spot that my lips are on. This could literally be my lips on my sister's tits.

What?

It was all very strange. Certainly my sister was beautiful, but I had never really thought of her that way. Well, certainly I had never thought specifically about her tits and nipples before! Chelsea was hot, I'll give her that. But she was my sister! We'd gotten along so well for so many years, I guess I just missed the phase where I was aware of her budding body!

But this was so sudden. My sister was suddenly thrust into existence alongside something to do with sex. I can't say I was turned off... I didn't know WHAT to feel. I was wholly unprepared for these thoughts.

God damn, Elise was hot. She now had her hand inside my underwear, wrapped tight around the base of my cock. It throbbed and I pushed her up higher on the bed. She was really doing a number on me and I wanted to favor her with vigorous oral sex. That was usually was did it for her as far as climaxes go, and I wanted to bring her there in a hurry.

I moved down between her legs, getting a close up view at the crotchless panties she wore to match the bra. God, what a sight. Elise truly had a perfect, young woman's pussy. She'd shaved it porcelain smooth for me in preparation, and the pink flesh flowered gently between the two purple seams down here, the green lace ruffling away from the center of her legs. I loved meeting my tongue with that smooth flesh.

I heard Elise sigh with anticipation, and in a moment I was on her, my mouth closing solidly over her open cunt. I felt lace and flesh and juice fill my mouth and gave a gentle suck of the whole mound before my tongue lashed inside, tracing the path my finger had taken minutes before, up into her twat. Elise moaned and squirmed on the bed, her ass lifting her pussy up into my mouth. I licked and suck and manipulated her lips with my lips as we both enjoyed the moment. I love licking Elise's pussy. I WAS licking Elise's pussy.

I was licking Elise's pussy through Chelsea's panties.

I was licking Elise's pussy through my sister's panties.

That's a fucking sexy thought.

What?

Well, I guess things had changed. I was now thinking things through in a very different way. I went through the same thought process I'd had over sucking Elise's tits, but things processed a little differently now.

"My lips and tongue are literally licking and sucking the spots that my sister's pussy has pushed against. My sister's pussy has filled this panty crotch before, her lips were where my lips are right now. Her pussy lips. My sister's soft cunt had been licked by some boyfriend right through these panties that I'm sucking on now. I'm sucking right on where my sister's cunt got sucked on before. This could literally be my sister's pussy in my mouth right now.

And with that something sort of broke. I was immediately slobbering over this cunt. My saliva dripped and mixed with my girlfriend's pussy juice as I slathered my face in this cunt and I thought about my sister's pussy! I felt the seams of the underwear rough in my mouth and I sucked them, knowing they'd caressed my sister's little pussy lips. Caressed her lips? Hell, these little strands had most likely been inside her pussy! Surely she's worn these before and she's gotten good and fucking horny. Her pussy has started to leak, and as she gets busy with her boyfriend these panties have surely pushed straight up into her cunt. She's probably worn them in every kind of position imaginable, stretching the material into her deepest, naughtiest crevasses. My movements grew larger as I lapped my way up and down the crotch of these panties, imagining Chelsea's pussy underneath it. Her pubic bone, her pubic hair, if she had any. My sister's pubic hair. My sister's bush. I wonder.

I nibbled and chewed and licked as Elise writhed above me, grabbing pillows with her spasmodic hands. She was lost in her world of pleasure, and I in mine. I forcefully shoved my tongue inside Elise's cunt, feeling the slight resistance of the panties against my lips. I lapped in and out, tracing the path that I imagined many objects had traveled in and out of my sister's cunt. My tongue delving through these panties just like a dick passing through these panties into my sister's pussy. My sister getting fucked.

My sister getting fucked.

I arrived at a new place when a full resolution image of my sister getting fucked on her bed wearing these panties flashed into my brain. I saw her on her back, tits pressing up against these bra cups, legs spread wide, and someone's huge dick fucking in and out of the hole in these panties, being gently chafed with each stroke. In and out of my sister's cunt. In and out of her pussy lips.

I suddenly wanted my dick sliding through these panties. I wanted my dick to be stroking in and out of a hole that had led to my sister's pussy. I wanted my sister's panties around my dick so badly. I emerged from Elise's nether regions and kissed her again, lining my dick up with her slick hole. I grabbed myself with a fist and slowly, achingly slowly, I slid myself into her. I bottomed out and felt the lace of the panties against my pubic mound. I sensed the labia pulsing around the base of my dick, and as Elise humped gently onto me I could feel that wonderful fabric clutching at my shaft.

I was in it. I was in this hole that had led inside my sister. I pictured it all in my head, my sister's legs spread, these panties spanning her lips, and my dick slotted up inside her opening. I opened my eyes and saw Elise splayed before me, and she changed... I pictured my sister's tits filling those cups correctly, I pictured my sister's pretty face, writhing and moaning. And then down below... I pictured her brother's dick, my hard, ready shaft, pumping in and out of her dripping cunt. A wet pussy that leaked gallons when it was being fucked by a big incestuous dick.

And that's when I shot a load of semen deep inside of Elise.

That word was what did it. Incestuous. Incest. A brother fucking his sister. Me fucking my sister. Me fucking Chelsea. My dick inside of Chelsea. God... how did I get here just from a pair of panties! My initial reaction had been nonchalance, and here I was climaxing in a fantasy of filling my sister's cunt. Incest. What a taboo. I'd never thought about it, but it suddenly was so wrongly hot. A big brother fucking his sister... she sitting on his cock, their sex juices mixing into a little sibling bond.

I opened my eyes and saw Elise panting beneath me, a huge grin on her face, and her hair askew. My dick continued to throb inside her, pinched ever so gently by the panties. I kissed Elise and exhaled, acknowledging how great it had been. I almost worried I'd gotten selfish and hadn't fully satisfied her needs, but was relieved when she said, "Fuuuuuck that was so good. I can't believe how you make me feel. I KNEW these panties were a good call. I'm glad I knew Chelsea had them. GOD that felt good! You were crazy. I can't believe how excited you were."

Yeah, I was excited all right. But holy cow, for what reasons!? Yeah, those panties were hot, but...

My sister.

I spent the next morning and afternoon pondering on these thoughts and fantasies. They hadn't gone away even as my dick shrank. I woke up and saw the infamous panties on the floor next to the bed and immediately pictured them on the floor in Chelsea's room, just one door away, sitting there after my sister had worn them. And the sex still intrigued me. All those naughty spots you're never supposed to see or touch on your siblings... suddenly sucked and fucked and touched a whole lot!

Elise and I spent most of the day in Central Park, had a nice dinner, and then after two glasses of wine we ended up in the bedroom again. Well, we were only BOTH in there for a moment before Elise said, "You wait right here. I'm gonna blow your mind again."

She tiptoed out of our room, a soft pink string bikini her only clothing. I heard a door open, then some sounds like a drawer, some more sounds, and then a gentle squeak as Elise came back into the room.

Only now she was wearing something different. Elise was wearing a neon green micro thong. Elise was wearing my sister's neon green micro thong. For the second time Elise chose panties from my sister's room and wore them to bed for me. God damn she was amazing. And those panties... you could barely call them panties! It was literally one string around the waist, another string cutting down the ass crack and then straight through the pussy, and the barest hint of a "triangle" right ABOVE the pussy. Not covering the lips at all, but a pointless attempt to cover something as the base of the triangle emerged straight from the pussy lips.

I wasted no time. I grabbed Elise by the waist and flung her on the bed. She giggled, thinking I was excited to see her wearing a brand new form of panties, but having no idea that the word sister lingered so strongly in my head. I knew I wanted it in my mouth again. I wanted this tiny little garment that had been wedged tight up against my sister's plump pussy lips, and all the way up her ass crack, past her brown hole, and around her waist. Elise again sighed as I dropped my head down. She enjoyed her ride as I fell deep into my fantasy again.

I grabbed the green material with my teeth, snapping it against her skin. What a flimsy piece of fabric. I can't believe this circled my sister. God, when would she have worn this? Certainly in foreplay for sex, like us, but could she have ever really worn them as panties for a day? Had she walked and sat and stretched and moved all while wearing these panties? The little string of the thong rubbing right up against her tight little anus.

Oh fuck. Oh Fuck. My sister's tight little anus. My sister's tight little asshole. This string material has rubbed back and forth over my little sister's wrinkled, brown butthole, many times. I wanted that butthole so badly. I wanted that little butthole. I shoved Elise up onto her hands and knees, pressing her chest down to the bed and lifting her ass into the sky. I saw the material stretch and pull directly over my girlfriend's own little sphincter. "Ooo," she said as she felt herself in the exposed position.

I looked at this wide open sight with my girlfriend's cunt spread from behind, a solitary green string slicing through her lips, and the base of that string hiding the essence of that dark little hole. I just went for it. I didn't even move the thong string to the side. I just lapped my tongue directly against it and against the anal opening on the other side. "Woo!" screamed Elise, who seemed surprised at the force. We were no strangers to some backdoor play, but it was certainly far from everyday, and we rarely engaged in it so brazenly. But I wanted that butt in my mouth.

I closed my lips on her sphincter, literally kissing her ass with my mouth. Only a thin line of green stood between full contact. Just as the night before, I devoured those panties. My tongue was over and under the thong, pinched tight against her anus by the elastic. I twisted it in and out, tasting every inch of that thong that had existed on my sister's naughtiest part. And I loved every minute of it. I just buried my face in my sister's ass (Elise's ass) while I fingered her from behind and jerked my dick at the same time.