Fucked my cheating-ass stepsis

I caught my stepsister setting up a date with some guy 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 riding to orgasm? I always wanted to fuck this slut, wish I knew she had such a great tight pussy before, I'd make a move on her long time before. Yeah, and she let me cum all over her ass too, wow!