Fucked my cheating-ass sister

I caught my sister setting up a encounter with some boy while her boyfriend was out of town and now this slut will do anything to keep me from telling him about it. If she cheats on her boyfriend in our house why it shouldn't be my dick she's sucking and railing to orgasm? I always wanted to bang this slut, wish I knew she had such a superb cock-squeezing pussy before, I'd make a stir on her long time before. Yeah, and she let me cum all over her ass too, wow!