My Sister's Birthday

Success. As if saying it rapidly might somehow erase the uncomfortable memory of it happening, my wife quickly blurted out: "She masturbated with that dildo, okay? I watched her do it... and now I need your cock."

My wife pulled her swimsuit down the rest of the way. The stubble of her mostly-shaved mound revealed itself, as well as her rounded pencil-sized lips.

I couldn't resist one last half-sarcastic poke. I repeated the expression that my sister had used earlier: "But what if my cock isn't available?"

"Shut up," my wife retorted. She pointed to the tent that had formed in my swim trunks. "Make it available."

I wasn't going to argue anymore. As I stood up, my wife crawled onto the bed. We almost always made love in some sort of side-lying or spooning position, as that was her consistent preference -- so she surprised me when she stayed on all fours and stuck her ass in my direction.

As I pulled down my shorts, my ready-to-go cock pointed straight at her rear end. "You want it like this?" I asked.

"Yes," she said. "You like doggy style, right?"

"Of course," I replied, eagerly lining up my tip behind her unusually-moist pink slit. "If that's how you want it."

"Uh-huh," she responded, reaching between her legs with one hand to spread her lips apart. At our age, it usually took a bit of foreplay for her to get fully ready, but she seemed ready... and she seemed to be in a rush.

I clarified that in the form of a question: "You want me in right away?"

"Yes," she responded. She backed herself up on the bed so as to force my tip to poke her.

Mostly to myself, I whispered: "Wow, what happened to you out there."

She was really wet... she was really horny..,. she was desperate for my cock... and so I gave it to her.

Without any resistance, every single part of my thick 7-inch cock disappeared into the tight, warm, soft, wet recesses of my wife's familiar pussy. I groaned in sensual satisfaction when my pubic bone pressed into her well-endowed ass and I reached the end of the line.

Usually I did most of the work, but -- apparently -- the sexual enthusiasm of my sister during that spontaneous poolside exhibition had somehow transferred to my wife. Pressing her elbows into the mattress, my wife began thrusting backward into me, slamming her plump ass into my crotch with a vigor that I had rarely seen before.

The sound of flesh slapping against flesh reverberated loudly throughout that small guest room. The mattress squeaked as her juicy snatch got pounded. She was gasping for air and moaning loudly with sexual pleasure. I grunted with each thrust into her familiar kitty.

Eventually, I had a growing sense that all of those sounds might have attracted a visitor.

Quickly glancing over my shoulder, I noticed that the door -- which had been closed -- was now open.

Without breaking the rhythm of fucking my wife, I turned my head a little more... and discovered that my premonition had been right. Standing there in her skimpy white two-piece with an amused smile on her face, my sister was watching us fuck each other... with one hand inside her bikini bottoms.

I had originally planned this trip with the intent of fucking my sister and cheating on my wife -- in an odd way, especially with her standing there, it now felt like I was cheating on my sister by fucking my wife.

And yet, certainly unlike how it would have been if the roles had been reversed, my sister did not seem opposed to watching me 'cheat' on her... in fact she seemed to be enjoying it very much. Perhaps she even hoped for it. She raised a finger to her lips to let me know that she wanted her presence to be kept a secret from my wife.

In the meantime, my wife's stance on the bed had shifted in a way that spread her legs further apart. By the expansion of her vagina, and by how she was moaning with increased intensity, I was confident that she was really close to cumming on my cock.

As I was often prone to do, I started talking dirty to her -- and this time, I also did so for the benefit of my eavesdropping sister.

"Are you gonna cum soon?" I asked my wife.

"Uh-huh," she gasped.

"Are you gonna cum on my big thick cock?... You like how I'm fucking you?... Taking you from behind?" She grunted strong affirmation to each of those questions.

Knowing that she was on the edge of an orgasm, I took it up a notch: "Did you like watching my sister fuck herself?"

"Yes," my wife confessed, breathlessly.

"Did that turn you on?"

My wife could barely speak. "Mmmm..."

She was spilling her private thoughts. I continued to dissect her mind: "Watching her made you horny, and then you knew you wanted my cock to finish you off?"

"YES!!" my wife exclaimed... but she wasn't just answering my question. With her legs -- and really, her whole body -- quaking feverishly, she cried out, "YES... YESSS!!... ohhhh... unhhhh..."

I felt the evidence of my wife's orgasm swirl around my embedded cock. This whole amazing encounter had me ready to go again. "Do you want mine too?"

"Uh-huh," my wife mumbled, suddenly spent.

"Here you go," I groaned, as a fresh load of semen departed me and shot deep inside her womb.

In the aftermath, I felt somewhat lightheaded and had to close my eyes for a few moments. By the time that I opened them again and glanced over my shoulder, my sister was no longer standing there.

I pulled out of my wife... which made cum start to leak out of her pussy onto the comforter.

"Tissues!" she cried out.

I obliged to her request, even though I knew my sister probably wouldn't care.

Holding the tissues between her thighs, my wife boldly ran naked out of the room to go to the adjoining bathroom. I collapsed into the corner armchair and stared in wonder at my cum-coated cock, wondering what had just happened and where things were going to go next.

+++++++

--- Saturday late afternoon.

Where did things go next? My wife decided to take a nap.

Although that indirectly provided my sister and I with some alone time, we declined the chance to attempt doing anything sexual together -- especially because we weren't quite sure what time her husband would return home. As she and I prepared dinner, though, we did find plenty of time to talk about all that had just happened.

My sister willingly disclosed additional details regarding her 'private' session with my wife -- and when I confessed that I had been watching them, my sister laughingly mentioned that she knew that from later discovering my 'contribution' on the window. My sister also revealed that -- after watching me fuck my wife -- she withdrew to her room and got herself off a second time. Her only regret, she said, was that it hadn't been her own tail on the receiving end of my cock.

Related to that, I admitted my earlier hesitation: "About that... it honestly felt like I was cheating on you. Especially when you 'caught' us. I appreciate how you -- apparently -- awakened my wife's sex drive, but I also want you to know that screwing her doesn't compare at all to how it feels to be with you."

My sister stopped chopping the carrots in order to face me. With sincerity in her eyes, she said: "I know that... and yes, this whole trip has obviously turned out much differently than what you and I expected. Part of me is happy that I stimulated your wife's repressed sexuality... honestly, I was really aroused by the chance to masturbate in front of her, and I secretly hoped she'd reciprocate... but more of me longs for the exclusive intimacy of our quarantine."

That comment hung in the air for a bit as we both reflected internally on the differences between this pair of visits.

"Do you think..." my sister started to ask something, but then stopped.

It soon seemed like she might not finish that question, so I asked her: "Do I think what?"

Her reply revealed why she had paused the first time. "Ok, this is crazy, but do you think that if we somehow seduced your wife into a threesome with us, that she would then be willing to let just the two of us be together at times? Or do we need to keep our thing a secret?"

I marveled at my sister's ingenuity, but I also knew my wife better than that. Smiling sympathetically, I responded: "Umm, no -- I don't think she'd ever be up for a threesome... and even if she was, she would never, ever, allow 2/3 of that to be incestual."

The expression on my sister's face indicated that -- while she probably expected that answer -- she was still disappointed. "You're probably right. I just thought that maybe if we enticed her to experiment even more -- together -- that she'd become open to the idea of sharing you with just me..." Her voice trailed off. "I just want more time with you, that's all. I wish we could go back to your basement and just be alone."

I reached for my sister's hand and squeezed it gently. "I know... I hear you. I've had the same thought. I think we're just gonna have to keep finding creative ways to be together." I then offered a faint glimmer of hope: "At the same time, I was extremely surprised by how much of a willing bystander she was today, so who knows?"

Smiling at the mere illusion of that possibility, my sister leaned forward -- as if to give me a quick peck on the cheek -- but then paused. With her gorgeous face in suspended motion only a few inches from mine, I began to drown in the beautiful blue-green pools that framed her pupils.

Something came over me.

And -- apparently -- the same thing came over her. "Remember what happened outside the airport?" my sister whispered softly.

"Yes," I whispered back.

"Did you feel something?" my sister asked, hesitatingly.

"Yes," I whispered again.

"Remember when we previously agreed to not kiss each other?" my sister asked with urgency in her voice.

I was pretty confident that I knew where she was going with this. "Yes," I replied, but then added: "... just like we also previously agreed to never actually fuck each other."

She smiled... and then bit her bottom lip to confess a forbidden desire for her brother. "Is this wrong?"

Her perfectly-plump lips looked so tantalizing. I shrugged. "I dunno... but I want to kiss you so bad." I corrected myself: "No, that's not true... what I actually want is to fucking make out with you."

The distance between us immediately disappeared. Non-accidentally this time, our sibling lips pressed together.

It was an explosion of intimate connection... one that felt like the completion of a high-voltage electrical circuit. Our first real kiss was passionate... enthusiastic... powerful... breathtaking... and erotic... a feeling rivaled only by the superior marvelousness of actually being inside of her.

I soon felt her lips subtly part. Our tongues introduced themselves to each other. I wrapped my arms around her waist and pulled her soft warm body tightly against mine, my rapidly-growing erection pressing firmly into her waist. I never knew that I had wanted this so bad...

"Honey, I'm home!"

With an alarming jolt, the singsong voice of her husband interrupted our newfound discovery. With a PTSD-like flashback to when my wife almost caught us in bed a few months prior, we immediately stepped back from each other and returned to attending to the food on the counter.

"In the kitchen!" my sister forced herself to call out cheerily, as if nothing had happened.

+++++++

--- Saturday dinner.

A bit later, when my wife eventually woke up from her nap and came out to join us, my sister and I were chatting casually with her husband around the dining room table. When I first saw her approaching, I began to feel a sense of anxiousness rise up within me. Would my wife say anything about what had happened by the pool? How would she act around us? Would she tell my sister's husband about the lewdness of his wife??

However, as we sat to eat dinner together and the evening progressed, it became clear that -- regardless of what might've been going on inside of her head -- my wife was going to pretend as if nothing unusual had happened.

At the same time, there was a second thing that became quite apparent: the unusually large amount of wine that my wife was consuming. If/when she ever did have alcohol, which was rare, even the tiniest bit would typically make her quite loopy and ready to pass out -- she usually quit after one drink. But this night? I counted at least 3 refills, and I might've missed some. Nervousness crept back in as I wondered what secrets she might spill while in a drunken state of mind.

And yet, in the midst of my wife's altered consciousness, there was a third noticeable thing that began to happen: seated at the table next to my sister's husband, my wife kept joking with... and playfully touching... him.

At first, I didn't think much of it, but -- when it persisted -- I eventually began to wonder: Is she... flirting with him?!? Right in front of us??

At one point, my tipsy wife rested her hand on his thigh -- dangerously close to touching something else -- which seemingly prompted my sister's husband to wonder the same thing. Looking somewhat flattered by her flirtatious attention, but perhaps also a bit uneasy about it, he jokingly commented, "I think you've had a little bit too much to drink tonight!"

My wife laughed, but the authentic content of her slurred response was profoundly revealing: "Oh... is that why you look extra handsome?"

While the face of my sister's husband turned red with embarrassment, my sister and I turned to look at each other with expressions of surprise written across our faces. What the heck was my wife doing?? But then -- out of nowhere -- I suddenly found myself having a very twisted thought.

I quickly shook my head. No, that was too messed up.

However, judging by the look on my sister's face, it seemed possible that she might actually be having the same wicked thought as me. In fact, she shot me a glare as if to say, Well??

Through a grimace, I silently conveyed my hesitation. While it might've indirectly granted some 'alone time' to the two of us, it was way too disturbing to think about enabling our respective spouses to... umm, get 'closer.'

But as I kept looking at my sister, her eyes quickly darted between her husband and my wife, then back to me... and then she made that face again. Well?? It was obvious now that we were having the same thought.

I was pretty confident that my wife had never cheated on me in the years we'd been together, but she did have an "emotional affair" (her words) with a produce manager that took a liking to her after she'd become a stay-at-home mom. When I had first learned that her frequent shopping trips weren't just for family groceries, I felt sick to my stomach, and I struggled with that betrayal for quite some time. If I felt violated then, it was even more unsettling to even consider the idea of allowing -- even worse, promoting! -- her to actually mess around with someone else.

And yet, at the same time, I realized that it was ridiculously absurd to be worried about my wife's infidelities when I had crossed every known boundary in order to fuck my own sister... right under my wife's nose, no less.

With that different perspective in mind, I looked back across the table at my sister and attempted to nonverbally communicate a new question: Are YOU okay with that?

Subtly, my sister nodded.

Holy fuck. What did we just agree to?!?

That whole private sequence had happened in less than a minute... but even if it had been longer or more obvious, the other two people probably wouldn't have even noticed, since they were so deeply engaged in drunken silliness. However, in order to increase the likelihood of success for the taboo plan that my sister and I had just developed, their looseness might need to be amplified even further. "More wine?" my sister asked both of them.

In unison, they raised their half-empty glasses... and then laughed stupidly about how they had done that in perfect harmony.

As my sister filled up their cups, she looked at me and smiled. This might actually work.

+++++++

--- Saturday evening.

Once it seemed evident that both of our spouses had enough alcohol in their systems to lose any remaining sense of decency and self-control, we needed to find a way to encourage the two of them to get alone... so that the two of us could be alone. It wouldn't take much: my wife was repeatedly fawning over my sister's husband, and he was now eagerly reciprocating.

At the right time, my sister presented what she had determined to be the best way to move things along. Softly laying her hand on her husband's arm and gesturing to my wife, my sister laid an adulterous trap: "Honey, do you know one of her interests?"

"What??" They both asked in unison... setting off another round of uncontrollable laughter.

"Stargazing," my sister answered.

I didn't think that was true for my wife... but then I realized that she was probably too drunk to disagree. Either way, I wasn't sure where my sister was going with that... until the next thing she said effectively connected the dots: "Why don't you bring her up to our bedroom and show her your telescope?"

I nearly choked trying to hold back my laughter at my sister's intended double meaning of his 'telescope.'

Her husband, with his red eyes looking quite glazed over, turned to my equally-tipsy wife: "You wanna see it?"

"Sure!" she said... a little too excitedly, I thought to myself.

"Well, c'mon then!" As he stood up wobblily from the table, he grabbed her hand to lift her to her feet... and as they stumbled out of the dining room and toward their upstairs bedroom, he didn't let go of her hand either.

Although the plan seemed to be working out perfectly, it felt more disheartening than I had expected to realize that I was probably watching my wife walk directly into an act of unfaithfulness. A part of me felt angry and betrayed to know that -- in all likelihood -- their little trip upstairs would end up with their clothes being off. For some reason, I graphically envisioned my wife -- for the first time in more than 14 years -- parting her naked thighs and opening up her married pussy to get split in half by another man's dick.

And yet, despite those uncomfortable feelings, I was also... hard. It was growing uncontrollably. Admittedly, I had sometimes had the 'cheating wife' fantasy, but I was genuinely surprised to find out that -- now that it might actually be happening -- I was indeed aroused by the thought of my wife opening herself to my brother-in-law.

I looked across the table at my sister. Whether or not she'd been having similar misgivings about the implicit permission she'd just given to her husband to fuck another woman, there was no undoing of the twisted plot that we had set in motion... which finally left us free to focus exclusively on each other.

"We were interrupted earlier," my sister stated calmly.

"Yes, we were," I responded with eager anticipation. Thoughts of my wife disappeared from my mind.

"I want to resume making out with you," she whispered tenderly.

"Me too," I echoed back.

My sister rose from her seat at the table. I was about to stand up with her, but she motioned for me to stay. Walking over to where I was seated, she swung her leg over mine and sat down facing me, straddling my legs.

I looked deeply into her eyes, and the passion that I saw burning there likely mirrored my own. With much less nervous hesitation this time, our necks strained forward and our lips joyfully reunited. It was bliss. Her mouth tasted sweeter than the sweetest honey.

Things escalated quickly. I slid my hands under her shirt to caress her back... but she must've felt that her shirt was an inconvenience, and so she quickly sat up straight to take it off. My sister was still wearing that tiny white bikini top from earlier. I switched the focal point of my kisses to what that top didn't cover, devoting my mouth's attention to the contours of her two rolling hills and the beautiful valley that lay in between.