Help find this 80s adult Comedy

Ok I’m looking for a late 70s-80s sex comedy I had seen taped on on a VHS when I was younger. I don’t remember any notable actors/ actresses but I do remember the movie opening with a guy having a conversation with a girl from his imagination, and later a scene where sorority girls are teaching a course on faking an orgasm. And a scene where they use sleeping gas on the dean in his car and to see if he’s really out a girl presses her boobs against his window.