The first time I saw my sister's Tumblr, I was just looking for her old photos from college. Instead I found a side blog full of brother-sister porn, captions about forbidden cock, and long, filthy confessions she had reblogged with comments like "this is exactly what I want."
Her name on it was "sisneedsbro." Mine was a throwaway I used for the same shit. We had both been posting and liking the exact same kind of brother-sister sex stories for months without knowing it.
I waited until our parents left for the weekend. She was in her room, door cracked, laptop open. I walked in without knocking.
She looked up fast, cheeks already pink. "What the fuck, get out."
I held up my phone with her blog on the screen. "Sisneedsbro, huh?"
Her mouth opened and nothing came out for a second. Then she laughed, short and shaky. "You found it."
"I run one too." I turned my phone so she could see my own posts, the ones describing exactly how I wanted to bend my little sister over and fuck her raw.
The air changed. She closed the laptop slowly. "So what now?"
I stepped closer. "Now you stop pretending you don't want your brother's cock."
She stood up. Her tank top was thin, nipples already hard. "Prove you mean it."
I grabbed her by the hips and spun her around, bending her over the bed. She didn't fight. She pushed her ass back against me. I yanked her shorts and panties down in one pull. Her pussy was shaved smooth and already wet, lips puffy. I ran two fingers through her slit and she moaned loud.
"Fuck, you're soaked," I said. "All those stories got you this wet thinking about me?"
"Yes," she breathed. "Every single one."
I dropped my pants. My cock slapped against her ass, thick and already leaking. I rubbed the head up and down her slit, coating myself in her juice, then pushed in hard. She was tight but took every inch. Her moan turned into a broken "oh my god."
I didn't go slow. I fucked her the way the Tumblr stories always described: deep, fast, rough. My hips slapped against her ass. Her pussy gripped me like it had been waiting years. Every thrust made wet sounds that filled the room.
"Tell me," I growled. "Tell me this is what you wanted."
"I wanted my brother's cock," she gasped. "I wanted you to find out and just take it."
I reached under her and rubbed her clit in fast circles. She came hard, legs shaking, pussy pulsing around me. I kept pounding through it.
When she caught her breath she pushed me back, turned around, and dropped to her knees. She sucked me straight into her throat like she had practiced on the fantasies. Spit ran down my balls. She looked up at me while she gagged herself on it.
"Feed me," she said when she pulled off. "Come in my mouth like the dirty brother you are."
I grabbed her hair and fucked her face until I unloaded down her throat. She swallowed every drop and licked the head clean.
We weren't done.
I put her on her back, legs over my shoulders, and sank back inside her. This time slower, deeper, watching her face while I bottomed out. She kept whispering the same filthy shit from her blog. "Fuck your sister. Fill your sister up."
I came again, this time deep in her pussy, pumping until it leaked out around my cock. She rubbed it into her clit and came a second time, clenching around me.
Afterward we lay there sweaty, her head on my chest. She scrolled through her phone and showed me a new post she had drafted weeks ago.
"Brother finally finds my Tumblr and ruins me. 10/10 would reblog."
I smiled against her hair.
"Post it."
She hit publish. The notes started rolling in before we even got up to shower.
We kept the blog. We kept fucking. Every new story we wrote together after that was one we had already lived.
