First Time Factor
The heightened arousal factor from a sexual experience with someone the first time, that usually wanes thereafter
Girl #1: I'm getting bored with JP Girl #2: You've only been with him three times! Girl #1: I know, but everything after the first time is a downhill slide Girl #2: You should just do one-nite stands then if you only get off on the First Time Factor Girl #1: Yeah maybe
By sarasplayroom.com