Fucking tight-pussy stepsis

How do I punish my 18-year-old stepsister for being mean to me, lying to our parents and cheating on her boyfriend? Hmm, now that I caught her sneaking back into the house at 8 a.m. when she wasn't even allowed to go to a party I can do anything I want, even fuck this slut right in the garden. Okay, we almost got caught there, but I got my dirty wish fulfilled a few days later and still fucked this bitch so good. Damn, her pussy is tight as fuck!