Turns out my stepsister Kiki is pretty slutty, you can kinda tell from looking at her. Especially pics of her sucking my stepdads's dick, that really gives it away. She seemed a little nervous & made up a bunch of lame excuses when I confronted her with them, but she was willing to listen when I offered her a deal. So up came her shirt, and out came her tits. I started touching them but lucky for her we almost got caught! The next day I approach her when she's on the phone. She's a little reluctant at first, but I remind her of the photos of her and my stepdad, so she starts jerking my big dick and letting me play with her tits while she's still on the phone. I get her to take her shorts off and start rubbing her pussy and she starts getting into it. She gets on top of my cock and starts riding me furiously! I make her turn around so I can see her ass and she practically twerks that thing on my dick.