She stormed into my apartment at midnight, eyes blazing, tits heaving under that tight tank top. "That bastard is fucking your wife," my sister hissed, slamming the door. "Caught them in our bed. We end this tonight."
I didn't hesitate. Years of tension boiled over. "Then we hit back the same way." I grabbed her, spun her around, and bent her over the kitchen table. Her short skirt rode up, flashing black thong barely covering her ass. I yanked it aside and shoved two fingers straight into her pussy. She was already dripping.
"Fuck yes," she growled, pushing back. "Make it hurt."
I didn't waste time. I freed my cock, thick and throbbing, and slammed it balls-deep into her cunt in one thrust. She screamed, gripping the table edge as I pounded her raw. Her walls clenched tight around me, hot and slick, juices running down her thighs.

I fucked her like I hated her, hips slapping hard, the table creaking under every brutal drive.
"Take it, sis," I snarled, reaching around to pinch her clit. "Your brother's cock is owning this revenge pussy."
She moaned filthy, "Harder, you fucker. Deeper. Show them what real family fucking looks like." I pulled out, flipped her onto her back, and rammed back in. Her legs wrapped around me, heels digging into my ass. I leaned down and sucked hard on her nipple through the tank, biting until she yelped. Her cunt spasmed, milking me as she came first, squirting around my shaft.
I didn't stop. I hauled her to the couch, bent her over the arm, and spread her cheeks. My cock, shiny with her cum, pressed against her asshole. "You want full revenge?" I asked, voice rough.
"Do it," she panted. I pushed in slow at first, then buried myself to the hilt in her tight ass. She clawed the cushions, cursing, while I railed her. Every thrust made her pussy drip onto the floor. I reached under and fisted her cunt with three fingers, double-penetrating her holes until she shook through another orgasm.
We moved to the bedroom. She rode me reverse, slamming her ass down on my cock while I slapped her cheeks red. "Tell me how it feels to fuck your brother for payback," I demanded.
"Like the best fucking revenge ever," she gasped, grinding her clit on my balls. I flipped her, pinned her wrists, and jackhammered her missionary style, watching her face twist in pleasure-pain. Her pussy sucked me greedily, creamy and loud with every wet slap.
I pulled out at the edge, fed my cock into her mouth, and fucked her throat until tears ran. She gagged but swallowed every inch. When I finally unloaded, I painted her tongue, her tits, then pushed back inside her pussy to pump the rest deep, breeding her as the ultimate middle finger to our cheating spouses.
We lay there panting, bodies slick. "Round two in the shower," she said, already stroking me hard again. "Then we send them pictures."
By dawn we'd covered every surface, every hole, every filthy position. Revenge never tasted so sweet or felt so tight.