A polite and gender-specific way to say fuck buddy (a term which can apply to male and female alike), both meaning a fairly regular sexual partner of whom no particular social commitment or romantic allegiance is expected. Very similar to "friend with benefits" except that if absoutely necessary the guy can be referred to as a "boyfriend" which, strictly speaking, isn't a lie.
Abercrombie? Oh, he's an honorary boyfriend at most. He gets nookie but I don't have to take him shopping. So far so good for us both."
"Am I still looking for a "regular" boyfriend? Sure, but for now Dolph keeps me satisfied sexually, so I know horniness is not going to interfere with my judgment choosing a real boyfriend."