Interesting question. “Man whore” or “himbo” are the go-tos. But these are just terms used to insult women reappropriated for guys. There’s “gigolo,” though no one has used that one since about 1984.
It goes back to the double standard where a women who has multiple sexual partners is automatically labeled a slut, while a guy who sticks his weenus into anything that moves is a super stud. At worst, he’s a player. But what he isn’t is a slut, a phrase that has been used to denigrate women since medieval times. (Ironically, the poet Chaucer used the word to describe a sloppily-dressed man.) You can see this double standard in action on every episode of MTV’s award-winning documentary series Jersey Shore.
So let’s come up with a few names for promiscuous guys, shall we?
10 Names For Dudes Who Sleep Around
The Herpes Express
Professor Hit It and Quit It
The Unsatisfying Sexual Experience featuring My Penis
“The DNA test says you’re my dad”
Itchy McGenital Region