A person who pretends to not be perverted, but really is.

Internet persona(s) who happens to follow you and you happen to follow them back and maintain communication with and have a mutual liking for eachother whether it be friendship wise, etc. (Mutuals if more than one mutual)

This term has its origins in Japan, where Japanese perverts share a common addiction: They love dirty school girl's panties.

NOT, and I repeat NOT the same thing as a gay man who hasn't left the closet yet.

Closet pervert is a term generally used to describe creepy men who seem as though they're hiding a nasty (very nasty) fetish from the world.

closet pervert - noun - Ebisu on Naruto