My Step-sis Let Me Fuck Her Ass to Remain Quiet!

Earlier today I went to check on my stepsister. I heard her fuck her boyfriend the other day and her stepmom doesn't want him to come over so I just wanted to let her know I was gonna tell her stepmom about it. Cause if she finds out and knew that I was aware of it I'm gonna get in trouble too for something I didn't do. Fallon wasn't stoked to hear that and really didn't want me to tell her stepmom. I had my mind set on what to do and I wasn't gonna let her talk me out of it. But then she offered to suck my dick for me to stay quiet, I thought about it for a second and realized it wasn't a bad deal for me at all, all I have to do is say nothing. She didn't wait long and was on her knees sucking my dick in no time, she must have gotten horny too cause we started fucking right after that. I fucked her missionary first before turning her around to fuck her doggy style. What I didn't expect is while we were in doggy she told me I could fuck her ass if I wanted to!