Thin Walls

As the week started, I found it hard to focus. Images kept flashing through my mind. Emma's flushed face as she watched me fuck Syd's mouth. Syd having her moans silenced by Emma's kisses. Emma handing us washcloths to clean the copious cum off our bodies. Syd's grin as Emma admitted how much she loved what we've been doing.

This lewd PowerPoint would play in my head, and then I'd blink and realize I'd missed the majority of a lecture or forgotten a bar-goer's order. I did my best to snap out of it, but it was no use. The thoughts of my girlfriend and my sister together had become a drug. I was addicted.

Syd and I would make out passionately after work and then she would smile and push me away. "I want us to build some anticipation, babe. It'll be worth it. Just be patient."

I would grumble and walk away, but it was for the best. I'm sure Emma was feeling the same way, and a little more excitement could only improve things.

By Thursday I'd become so consumed with school and work that I was finally able to think about things other Emma and Syd. It wasn't like I'd forgotten about what we did or the upcoming surprise, but I was able to get through the day without getting so distracted with horny memories that I fully malfunctioned.

And when I returned to the apartment I was too busy thinking about something I'd just learned to notice Emma and Syd smirking about something they'd been discussing. They were making dinner, and it didn't occur to me until we were all sat down enjoying it that this might be the night of the surprise. Dinner conversation was fairly normal, for us at least. Flirty and familiar, but nothing special.

My hopes about the surprise were dashed when Emma said she'd be heading back to her room for the night to tackle some homework. She kissed each of our cheeks and then disappeared.

As we had a few nights this week, Syd and I ended up making out, this time on the couch in the living room. But this time Syd didn't pump the brakes once things started getting hot and heavy. I wondered if Syd was just too hot for me to keep up the anticipation game.

Soon enough Sid was on the floor, kneeling between my legs, desperately pulling off my belt and pushing my pants down. My cock was halfway down her throat before I knew it.

Usually this sequence of events would lead to a few minutes of enthusiastic cock-sucking before Syd would stand, disrobe, and impale herself on me.

But not this time. She was slurping, slobbering, gagging. Using every move. Once she heard me moaning she started using her hands and mouth in concert, the same way she usually did when she was trying to finish me off. I felt like a game being speedrunned. I might have said something if it didn't feel so fucking good. Sydney seemed incredibly excited that I was close. Despite still being fully dressed, her tits and pussy untouched, her moans, muffled by the cock in her mouth, were almost as loud as my own. I briefly felt bad for Emma, who must have been struggling to focus on her work. But at the same time we were all long past feeling shy or apologetic about the sounds heard through this apartment's walls.

When Syd heard me roar and then begin filling her mouth, she moaned so loud I wondered if she was cumming tantrically, untouched, just from witnessing my own orgasm. With each throb of my cock she'd growl out another moan. She looked up at me with fire and mischief in her gorgeous eyes. As the muscles in my groin stopped clenching, she pulled back, clearly being careful not to spill anything.

When I would have expected her to tilt back her head and make a big show of gulping, or perhaps open her mouth to show off the pool on her tongue, she instead reached down to knock in a rhythmic pattern on the hardwood floor.

As soon as she was done, Emma's door swung open. She came out wearing her normal pajamas, walking right towards us. Even just a few days ago I might have instinctively moved to cover myself in front of my sister, but we were beyond that now. And anyway, Emma seemed to only have eyes for Sydney, who was now standing and turning to my approaching sister.

I didn't realize what was happening until it was happening. Emma walked right up to Sydney, embraced her, and pulled her into a kiss. Not a peck. I couldn't see it happening, but I knew Syd was pushing my load into Emma's mouth. Emma didn't flinch. In fact, she groaned, as if her life depended on swallowing every drop.

Their kiss was a hungry, needy kiss, and it went on and on, my sister and my girlfriend moaning softly into each others' mouths. I imagined my cum trading between their mouths, back and forth, forth and back.

And when they finally pulled away from each other, Emma turned to me, opened her mouth, and showed me that all of that cum had ended up with her. Then she closed her mouth and swallowed.

"Thanks for dessert, bro." She and Syd exchanged a mischievous grin.

I was shocked. Stunned. Dumbfounded. And horny. So, so horny.

Emma licked her lips and made a yummy sound. Then she kind of shrugged. "... But I do actually have a ton of work to do." She pouted and blew me a kiss before retreating back to her room.

In stunned silence I turned to look at Sydney, who did an adorable little curtsey and said, "Surprise!"

I shook my head and blinked a few times. "That... was incredible. And not what I was expecting."

Syd plopped down onto my lap. "I know! What did you expect? Was this not better?" She grinned.

I laughed. "Much better."

"I thought about springing it on both of you, but I figured it was better to make sure she was into it. Luckily she was *very* into it." My heart skipped a beat at the thought that my sister had been so excited to eat my cum.

My eyes unfocused as I thought about that, but then I remembered I had a beautiful, horny woman in my lap.

I looked at her with intensity. "Get on the bed and take your pants off."

She gasped, then smirked. "Yes sir."

I ate her out until I was hard again, getting an orgasm out of her in the process. And when I was ready to go, I flipped her over onto all fours and pounded away. Knowing Emma, with my cum in her belly, could hear every moan, every spank, every grunt only made it better.

I fucked Syd to another orgasm, then filled her with cum. When I finally pulled out, some of my cum followed, dripping out and onto the sheets below. She collapsed onto the bed, her ass and pussy in the air, oozing a puddle.

"This is quite the sight." Syd giggled, and then turned to lay down with me. We were quickly asleep.

That weekend Sydney had a lot of work to catch up on, so she decided to spend it back in her dorm to avoid distraction. She gave me a long kiss before leaving. We'd gotten so used to essentially living together that a weekend apart felt like a lot. That said, it was probably good for us to spend time on some of life's other commitments.

Once she was gone, I figured I'd get ready for the day, but I could hear the shower running, so I sat down in the living room to watch TV.

I got engrossed enough in whatever I was watching that I didn't notice when the water shut off, when the blow drying ended, or when the door opened. It wasn't until I heard Emma speak that I turned around.

"So it's just you and me this weekend, huh?" She didn't say it particularly flirtatiously, but paired with her current state of dress, I couldn't help but let my horny mind wander. Emma was wrapped simply in a towel. Her hair was perfect, and she'd clearly put on some makeup. Over the years I'd seen her hundreds, maybe thousands of times in a towel. Maybe she just looked particularly good today, or maybe it was an effect of our developing relationship, but I couldn't stop staring at her.

She just softly smirked at me. After a moment I realized she'd asked me a question.

"Uh... yeah, I guess," I sputtered out, dumbly.

Looking poised as she stood beside the couch, she responded, "I was thinking it could be nice to do a movie night tonight, just like old times."

I managed to regain enough composure to reply more eloquently this time. "That sounds really nice Em, I'd love that."

She grinned. "Great! Then I'll get some work done now so we can have the night free."

With that she spun and walked back to her room. My eyes followed her every step of the way. Before closing her door, she noticed I was looking and met eyes with me. With an inscrutable look in her eye she played with the top of her towel. I wondered if she was about to let it drop in front of me. My mouth felt suddenly dry.

Then she just closed the door. I let out a sigh and turned back to the TV. I shook my head and smiled to myself. Life had gotten truly wild, not that I'd change it for anything.

For the rest of the day I got some homework and chores done. Emma came out of her room to join me for lunch, during which we decided on delivery pizza for our movie night dinner, to really recreate the experience of our younger days. Emma also picked out a movie for us, some bank heist movie that was supposed to be good.

We both got some more done before nightfall, and then it was time to order dinner. I called in our usual order, and Emma downloaded the movie. Once the pizza arrived, we poured ourselves big glasses of soda, placed the pizza box right on the coffee table, and started the movie.

It really did feel like old times. So much had changed in the past several months. Saying goodbye to friends we'd been in school with our entire lives. Leaving behind our childhood home and our parents. Making a life in an entirely new place. Dealing with the pace of college. Getting jobs. And that's all without mentioning the new, increasingly taboo element of our relationship. I wouldn't change any of it, but this little slice of normalcy felt like a much needed balm.

Eventually the pizza was gone and our glasses were empty. I sat back into the comfy couch, and Emma did too. But this time it was a little different than those nights back at home with Mom and Dad.

This time she cuddled into me. Instinctively I wrapped my left arm around her, pulling her in. She rested her head softly on my shoulder. I heard and felt her let out a long contented breath.

As much younger kids Emma and I had certainly cuddled. But as we'd aged into young adults it became less common. At this point I couldn't remember the last time I'd held her like this. And it had certainly never felt like this.

For a while we just sat there like that, watching the movie as we held each other. I definitely missed portions of the movie as my mind was consumed with the feeling of my sister's body against mine.

I'd occasionally give her a little squeeze and she'd smile. And then I'd feel her hand gently caressing my thigh. After a while she turned her face, resting her cheek on my chest and looking up at me.

"Isn't this nice?" she whispered.

"Very nice."

She sighed and continued watching the movie. I tried my best to focus on the screen as well. For a while it worked. I was absorbed into the movie, momentarily forgetting the soft warmth of my sister pressed against me.

My attention was pulled back when I realized she was looking at me again, her brown eyes surveying my face, her teeth pulling at her bottom lip. She seemed deep in thought.

I lifted an eyebrow. "Everything ok?"

Her eyes fluttered, as if she was waking from a dream. With a smile, she took a deep breath and let it out. "Yeah. Better than ok." Her eyes kept fluttering around my face. Her fingers started playing along the line where my t-shirt met my neck. She opened her mouth to speak, but the words didn't make it out. Instead she flicked her tongue across her lips, making them glisten in the flickering dim light of the movie, before she bit down on her bottom lip again. She looked so cute as she chewed on whatever thought was clogged in her mind.

I was about to laugh and make a joke when she finally blurted it out.

"I probably shouldn't kiss you, right?" She immediately blushed in response to her own question.

There was a lot packed into that one sentence. The idea that she *wanted* to kiss me. The idea that there was something preventing us from doing that. The idea that if it weren't for that something in our way, we'd probably be making out right now. And finally that last word. "Right?" As if I could just say, *Actually, we probably should.*

But before I could act on rash impulse, or even really take a moment to consider, a face appeared in my mind. Blue eyes, blonde hair, sloped and pierced nose. Sydney. At that moment my eyes flashed to our bedroom door. She wasn't there, but it was like I could feel her presence, and I was looking to it for permission.

Emma saw that flick of my eyes, and, in that way twins sometimes can, she read my mind. "Yeah." She nodded, a hint of sadness seeping into the corners of her eyes. "Yeah." She looked away.

"Hey." I said quickly. I grabbed her cheek and gently turned her head back to meet my eyes. I leaned my face down toward her, and I heard her gasp as her lips parted.

But I turned and kissed her cheek, lingering a bit longer than a normal brotherly peck. Emma sighed as I pulled back. I met her eyes again. "I want to, too." Her eyes looked a little glassy as she nodded and smiled thinly. "I'm pretty sure if Syd was here she'd want us to." Emma chuckled. "But she's not. And it's probably not the kind of thing we should ask permission for over text message."

Emma laughed. "For a few reasons!"

I grinned and nodded. "Exactly."

Emma nodded again. She looked up at me and once again I watched her lick her lips.

She leaned forward and this time it was her turn to plant a wet, lingering kiss on my cheek. She held my neck as she did, an intimate gesture that made me shiver.

She pulled back. "You're right. I hate it, but you're right. You're a good brother. And a good boyfriend." She blushed and added, "To Sydney." I couldn't help but laugh. "I love you, Ben."

We hugged, and I whispered back, "I love you, too."

When we separated, she was looking at the screen again, just in time for the big climactic action scene. Engrossed in the movie again, we passed the rest of the night in a comfortable cuddle.

When the credits rolled, Emma stretched and groaned. "It's been a long week. I think I'm gonna head to bed and catch up on sleep." This was early for Emma, who tended to be up late with Syd and I or with one of her... visitors. But it had been a busy week so I didn't think too much of it. In fact, a calm early night didn't sound so bad after all of the excitement my life had been throwing at me.

"Sounds good. I'll tidy up a little, then probably do the same."

Emma smiled then gave me one more peck on the cheek. "Night, bro." She popped up and headed to her bedroom.

I collected the pizza box, our empty glasses, and a few other things as I my mind reflected on the night. Our cuddle, both comforting and thrilling. Emma's question. My reaction.

I was both excited and anxious to talk to Syd about what just transpired. I figured she was probably still heads down on her work, so it'd have to wait. But I texted her to make plans to meet up the next day.

With thoughts of my girlfriend and my sister swirling in my head, I laid down into bed and turned off the light. I'd become accustomed to sleeping alongside Syd, so the emptiness and calm felt odd, even oppressive. But that silence didn't last long.

Through the thin wall came a sound, low but distinct. A buzzing. Like an electric toothbrush or a nose hair trimmer. Or a vibrator.

At first it was just the buzzing. Then the occasional squeak of a bed under a shifting body. Then a moan.

I closed my eyes and tried not to listen, but how could I not? How could I not imagine my sister pleasuring herself with the aid of a toy? How could I not picture her in her underwear, legs spread wide, panties pulled aside as the silicone made contact with her soft, wet lips? How could I not imagine her free hand roaming across her body, pinching her nipples and gripping her curves?

The moans escalated in volume and frequency. Soon words joined in. "Fuck yes..." "Give it to me..." "Oh god!" My horny sister was no poet, but it was enough to have me stripping off my boxers and gripping my rock hard shaft. I was quiet at first as I stroked myself, but I figured it would only be right for me to contribute. I stopped holding back my moans and let the low grumbling noises fill my room. Emma clearly liked that because she got noticeably louder and more excited.

I could tell she was close, and that had me close too. When she finally shouted, "Oh FUCK yes, Ben!" I couldn't hold back. I let out a loud strained moan and shot cum all over my own torso. My senses were overwhelmed, but I could still hear my sister wailing out her own orgasm next door. My body trembled and tensed as I came and finally began to relax into the bed. I could faintly hear Emma's moans recede into deep breaths and pants.

I blindly reached for a tissue to at least minimally clean myself up. As I mopped up the cum, I heard Emma's sweet voice, "Night bro." I could almost hear her winking. God, all I wanted was to march over to that room so she could clean me up and get me dirty again. That thought, about my own sister, might have freaked me out a few weeks or months ago. But now it felt like a barely suppressible urge.

Those thoughts might have kept me up, but the calming magic of my own strong orgasm pulled me to sleep.

The next day I woke up and immediately felt a bit dirty, covered in the bits of dried cum that had been left after my sloppy clean-up the night before. I quickly made my way to the shower, where I couldn't help but reply last night. The movie, the near-kiss, the pre-slumber fun. Then Syd's face flashed into my mind again. I was pretty sure I hadn't done anything wrong. In fact I'd stopped us before we did anything Syd hadn't explicitly approved. But it was hard not to feel anxious. Navigating feelings in a two-way relationship was hard enough. Adding a third party was no small thing.

I finished getting cleaned up and dressed. Emma was apparently out for the day, so I just focused on getting some of my own work done. Soon enough it was time to head out. Syd had asked that I pick up a few sandwiches from our favorite nearby cafe and bring them over to her dorm so she could take a break with me without losing too much valuable work time.

The campus was gorgeous and bustling as usual. It was the perfect place for a young, bright person to be. I'd been in a good mood since waking, but my heart felt a bit lighter with the sun and the beauty of the place.

Soon enough I was knocking on her door, which was opened by a very small black-haired girl that I'd learned was named Julie. "So here's the guy that stole our roommate."

I made an apologetic face and opened my mouth to defend myself before Julie's deadpan face broke into a smile as she laughed at my discomfort.

"Just kidding, she's in her room." She gestured me in. Syd's other roommate, Becca, smiled at me from the couch.

I knocked and then walked into Syd's room, and as soon as she saw me she launched up from her seat at her desk to suffocate me in a hug and lingering kiss. "Mmmm, I missed you!"

I laughed, "It's only been a day." She rolled her eyes, and I chuckled. "... but I missed you, too."

She looked at me sweetly, and then I saw her eyes open when a familiar scent hit her nostrils. "Oooh, sandwiches! I'm fucking starving."

We immediately got down to eating, pausing only for brief conversation. Syd told me about how busy she'd been with homework. The meals she hadn't skipped had been pretty bare bones, so this food was sorely needed.

When the food was gone, Syd looked at me and let out a cute little belch, before covering her mouth and apologizing. I laughed and told her not to worry.