I Fuck my step-SISTER While my Wife Watches

My wife knows I've had a porn obsession for a while now. I always sneaks off as if she doesn't know what I am up to. One day she was curious and at least wanted to see what kind of porn I watch... Well, she figured out it's all taboo step-sibling fetish porn. She confronts me about it, and eventually, I break down and tell her that when I was younger that my step-SISTER and I used to fool around and experiment with each other. I tell her we had pretty much done everything, all through growing up. I admit that I still fantasize about it, and that it's on my mind all of the time. After hearing me open up completely, about an OUT THERE fetish surprisingly got her horny, so.... She decided to make me an offer, to stop being secretive and watching porn depicting step-sibling sex, that we should just invite my step-sister over and do the real thing (while she watches). We bring her over, and eventually tell her why she is there. She reluctantly gives in, after realizing she is just as into the things we used to do as I am. We suck, fuck, all while my wife stands there watching and playing with herself. The only slip up is that I accidentally cum inside my step-sister, fortunately I was nice enough to clean it out of my with my mouth. In the end, everyone got what they wanted, and next time... MY WIFE'S GOING TO JOIN IN.