In the Season 3 Episode 4 Confetti Deathblow with Petey and Cookie mistake each other for being gay they believe they need to get the other to be straight again so they won't go to hell, so they try and seduce each other.
It began with Petey masturbating with his door open so his mother would come and see, after seeing that Cookie did the same thing about half-an-hour after, which made Petey think he was turning her on and she was becoming straight.
Later it ends with the two fucking in the living room which Gina and Theresa walked into and watching them go at it.
