You found a video tape and decided to see what was on it. It turned out to be an erotic video of your parents, where your step-mom gets a close-up shot of her ass and teases your step-dad. She's squeezing and spanking herself, oiling herself up and saying dirty words. She teases step-daddy with her asshole and asks him to fuck her anally. This dirty video of your parents drove you crazy and got your cock up.