Sister's Surprising Discovery Ch. 04

2020 was of course a memorable year for everyone, but for my sex life it was turning out in ways I would never have dreamed of.

It all started with me changing from just a reader of erotic stories to a writer. My stories involved my sister and step mum, and things definitely changed when my beautiful blonde sister discovered these stories and, even more surprisingly, reacted by sleeping with me rather than the disgust I expected.

That was the start, but really I should have called this "My surprising discovery" as things escalated from then on in ways I would never expected.

Not long after I had started having sex with my sister, my step mum discovered that my dad had been cheating on her with her own sister. Dad was/is a bit of a shit to be honest, so although Beki and I are 18 and 21 years old respectively, we stayed with our step mum rather than leave with dad. Again, much to my surprise but at Beki's encouragement, we ended up comforting our step mum and seducing her into a three-way sex session with us.

Because of covid lockdown, I had a few months where I was either fucking my sister or my step mum and seeing virtually no-one else. Some people might say this was wrong, but I didn't care. I loved it. My sister is a bit of a sex freak and would fuel my perverted fantasies, including getting back at dad by seducing my hot aunt as well once we could. I never imagined that this would turn into a big orgy involving not just my sister and step mum but two of my friends ganging up on Aunt Kath and fucking all her holes. We never did send the video of this to dad like we had planned, but Aunt Kath left him and moved in with us so this worked out better than I could have hoped. My young cock had never seen so much action!

My best friend Carl had helped me to gangbang my aunt, and he also had a sister who was friends with my sister Beki as they both attended college together. His sister Gemma was quite hot, and before Covid (God, was there such a time?!) I'd had a bit of a crush on her. After the incident with my aunt, during which Carl had also had sex with my mum and my sister, I found out that Carl had a crush on his sister too! Of course, when we told my big titted sister Beki about wanting to double team Gemma and introduce her to fucking her brother (and me of course!), Beki was all for it. As long as she could join in and make it a foursome naturally!

It turned out that Beki had already fooled around some with Gemma. At first I was a bit jealous that she was fucking anyone other than me (at least whilst I was there!), but as she said I had mum and my aunt Kath to entertain me so it was good that Beki was developing other interests! Beki also said she could hook me up with some of her friends if I wanted. Part of me wanted to say I could get girls myself, but then I remembered that Beki was friends with a lot of hot 18 year olds and realised I would be a fool to say no. I have already had a hot session with a couple of gorgeous 18 year old twins, but that is another story!

The plan to pull Gemma into our circle of crazy sex seemed riddled with holes to me, but Beki was sure it would work and we had lots of back up plans just in case. In the end, it worked out better than we could have hoped.

It all started with Carl coming over early one Friday evening and disappearing upstairs with Beki. Gemma arrived about an hour later on the understanding that she was going out with Beki for a drink and then to a club. Gemma was blonde with nice c cup tits that were straining against a very slutty low-cut top and had me hard as soon as I opened the door. I lied and said Beki didn't seem to be in and invited Gemma into the lounge with me to wait. Being a good host, I got Gemma something "for the road" whilst we waited and I proceeded to lay on the charm. There had always been a bit of a sexual undercurrent with Gemma and I, and I was suddenly way more confident after my experiences with the females in my family the last few months. It didn't take long before I had my arm around Gemma and was leaning in to kiss her passionately. After a while of making out and getting Gemma hot and bothered, I suggested we take things upstairs. Gemma didn't notice me text my sister that we were on the way up and to move on to the next phase, but I knew the next few minutes were crucial.

Right on cue, Beki let out a deep moan as we ascended the stairs.

"Sounds like my sister is home and up to something after all!" I whispered to Gemma in mock surprise. Beki had left the door to her room slightly ajar, so I had little difficulty in getting Gemma to keep quiet and peak through her door. I don't know if Gemma was prepared for what she saw though.

My sister was lying on her bed naked from the waist up with a boy's head cradled into her chest. I of course knew this was Carl, but Gemma couldn't tell anything at that point other than the fact that it was a boy and he was as naked as the day he was born. Maybe if she had looked closely enough she would have realised it was her brother, but she stood rooted to the spot as she realised that Beki was having her tits sucked.

Beki moaned again as Carl switched from one tit to the other on top of her.

"That's it baby, feast on my tits. Oh God, so good..." cried Beki as she played up for the audience she knew was there. I think Gemma thought she was out of sight, but as she went to step away I wrapped my arms around her and kissed her neck.

"Let's stay and watch," I whispered in her ear as Carl kissed his was down my sister's belly and moved towards her wet snatch.

I continued to kiss Gemma on the side of her face and neck as I reached around to play with her breasts through her top. Gemma moaned as she realised that Carl had moved down to lick on Beki's pussy, but Beki covered for her by moaning out loudly herself as Carl went to work on her moist sex.

"That's it Carl, eat my cunt! Lick me!" cried Beki as Carl started thrusting his tongue into Beki's sex and reached up to rub her clit with his fingers. I felt Gemma tense up as my sister said Carl's name and she suddenly took in the fact that it was her brother than was on to of Beki and bringing her off, but I chose that moment to slip my hands underneath Gemma's top and start massaging her sensitive nipples whilst still kissing her neck and holding her in place.

"I'm cuming!" screamed Beki as Carl licked frantically at Beki's opening and drank up Beki's girl juice as fast as he could. Beki looked at him and smiled. "Now it's your turn," she said, getting Carl to sit up on the bed and plunging her head down his engorged shaft.

Beki had a bay window with the curtains drawn and I whispered in Gemma's ear that we could sneak over to this without being seen and get a better view. I hadn't really believed that Gemma would fall for this, but I guess that with the visuals before her and my ministrations Gemma wasn't really thinking straight and we snuck across the room and behind the curtains. I was amazed that Beki and Carl could act as if they couldn't see us, or that Gemma could believe as we opened the curtains slightly to peer out that if we could see them they couldn't see us.

"Shhh, be quiet," I encouraged Gemma as I worked to peel her top and bra off and expose her magnificent breasts.

On the bed, Beki was doing her best to swallow all of Carl's dick. I was quite proud that he wasn't quite as big as me, but he was still a decent size and Beki was gagging a bit as she fed his cock into her throat. As we watched them, I played with Gemma's exposed tits with one hand whilst slowly working on her skirt with the other. Gemma was breathing heavily now as she watched my sister bob up and down on her brother's prick whilst I stroked the wet patch on her pants and slid my own trousers off. My own cock felt like an iron bar, and I knew Gemma could feel it poking at her moist teenage hole through the thin material of her panties.

As Beki picked up her pace in sucking off Gemma's brother, Gemma didn't offer any resistance as I removed the last remaining piece of clothing from her and slid out of my boxers. The neighbours could have had quite a show if they'd been looking, but this was the furthest thing from Gemma's mind and I knew it was only our closest neighbours who could see in anyway even if they had been looking.

Beki pulled herself off Carl and moved over to sit down on top of him and his 6-inch dick.

"Yes, fuck me!" she moaned as she began to ride up and down on Carl's stiff cock. Gemma could no longer suppress her own moan as I rubbed my cock back and forth on the entrance to her sex, the two of us still stood behind the curtains and watching our siblings fuck each other like there was no tomorrow.

I reached forward and slipped a couple of fingers into Gemma's tight pussy. God, she was practically gushing. I lined my cock up to her front entrance and with one thrust I plunged myself fully into her and pushed her forward onto the bed.

Gemma cried out from the shock of my penetration and the fact that she could no longer pretend that Carl and Beki did not know she was there. Beki rolled off Carl, which left Gemma's head level with Carl's cock as I stood up and continued to fuck in and out of her teenage pussy with measured strokes.

"Hi Gemma," giggled Beki. "Do you want to join in?"

Before Gemma had a chance to even think, Beki grabbed hold of Carl's cock and guided it to Gemma's lips. Almost on instinct, Gemma opened her mouth and began to suck on his stiff prick before she realised what she was doing and tried to pull away. I knew she was too far gone though and leaned forward to hold her head in place as I reamed her wonderfully tight cunt from behind. Sure enough, the attempts to pull away grew weaker very quickly, and we knew we had her.

Beki got off the bed and kneeled at my feet as I was leisurely fucking Gemma from behind. I smiled and eased my throbbing member out of Gemma and fed it to Beki's hungry mouth. Gemma didn't stop sliding her lips up and down her brother's penis as I began switching between my sister's hot mouth and Gemma's tight pussy.

After a while, Beki lay beside Gemma on her stomach with her bum on the side of the bed in a mirror image of her friend and Carl got up and slid his stiff knob back into Beki's willing pussy. Side by side we began pounding each of them as we marvelled at the feel of their clutching vaginas.

After a few pumps, I nodded at Carl. It was time to switch and give Carl the opportunity to screw his own sister. Beki grabbed hold of Gemma's hand as we both pulled out of their respective holes and moved across to both sheath ourselves in our sister's sex. Gemma moaned out loud as she felt her brother's cock fill her up for the first time.

"Yes, fuck me big brother!" she cried as Carl worked himself in and out of her cunt with increased passion.

Beki and I were both loved how the plan had worked out as we fucked alongside them. I reached forward and played with my sister's clit as I picked up pace and began pumping in and out of her.

"Cum for me, my sister!" I urged her as I rubbed around her hot sex. I saw Carl too was rubbing his sister and felt my balls beginning to boil. Almost synchronised. we all came as Carl and I spewed a mass of cum into our orgasming sisters.

As we calmed down, we lay on the bed for a while holding hands, me with Beki and Carl with Gemma. I could tell that Gemma was struggling to come to terms with what had happened, so we gave Gemma an edited version of the last few months. We didn't need to tell her about our step mum or aunt, but as I told her about Beki and I she sort of calmed down. Of course, when I say "calmed down", her change in mood might also have been because she had Beki and Carl playing with her tits as I talked, although I prefer to think it was my powers of persuasion.

Beki crawled down to Gemma's crotch and began to lick at Gemma's wet pussy. Carl and I just lay for a while as we watched Beki expertly eat out Gemma's steaming sex and Gemma began to moan deliriously with pleasure.

Carl was fully hard again and guided his sister's hand onto his stiff prick. She stroked it lovingly as he leant forward and sucked one of her breasts into his mouth. Beki disappeared briefly, but Gemma hardly noticed as she pushed Carl down on his back on the bed and mounted him. I stroked my own cock as I watched my best friend enjoy having his sister ride him whilst I waited patiently for my sister.

Beki returned carrying some lube, and I slowly started rubbing this onto my cock and into Gemma's tight bum hole.

"What are you doing?!" Gemma cried out in alarm, having never even thought about anal sex.

"Relax, you'll love it," said Beki, sliding up to Gemma and kissing her fully on the lips.

Gemma continued to bounce on top of her brother whilst Beki made out with her and I guided one and then two fingers into her asshole. God, she was tight, but I definitely felt her loosening up as I added a third finger into her back passage and made it nice and wet.

Carl held Gemma still as I final manoeuvred myself so my dick was prodding at Gemma's back hole. Slowly but surely, I began to push past the resistant muscle of her sphincter ring.

"Ah, it hurts!" cried Gemma, pulling away from Beki's probing tongue.

"Just relax, it hurts at first but then it feels great," replied Beki as she held Gemma's head. I'm not sure if Gemma believed her, but I was not about to stop now. Beki silenced any protests by leaning in and kissing Gemma and making out with abandon. Slowly but surely, I fed inch after inch of my engorged member into Gemma's shithole till I was fully buried in her back passage. We sat still for a while, then Carl and I started to slowly slide in and out of her fuck holes, separated only by the thin membrane between her pussy and her arse.

Gradually, Gemma's groans became moans as she began to enjoy being double stuffed by her brother and I. I reached around to grab hold of Gemma's swinging tits as Carl leant in and kissed his sister. At the start, Gemma had been hesitant about her brother, but now she kissed him back without restraint.

"That's it, fuck her harder!" cried Beki as she sat beside us and thrust her fingers in and out of her own pussy rapidly. Carl and I picked up speed till we were basically slamming in and out of both of Gemma's holes and she flopped between us, lost in her own lust and passion. I knew I was about to cum again, and pulled out and plunged into Beki's spasming pussy as I erupted with what felt a gallon of cum. Carl rolled over and pulled out of Gemma, took hold of his cock and blasted a load of his cum over his sister's face.

As both Carl and I sank onto the bed spent, my sister and Gemma cuddled together and Beki started licking Gemma's face before feeding Carl's cum to her.

"You're going to love fucking your brother," said Beki. "There is nothing quite like it!"

"So true," I thought as I closed my eyes and felt myself drifting to sleep dreaming of lots more sexual adventures to come.