What is "fag stag"

n. (context slang vulgar English) A heterosexual man who socializes with homosexual men

Fag stag and fruit fly are slang terms for a heterosexual man who either enjoys, prefers the company of (or simply has numerous friends who are), gay or bisexual people.

The latter term comes from the derogatory term for homosexuals (fruit).

The term, which originated in the United States in the 1990s, is the male equivalent of the more common slang - fag hag, a term which is part of hag-ism; the identification of a person with a group—usually united in terms of sexuality, gender identity, or shared sex—of which he or she is not a member.

The term can be used as a pejorative or as a term of endearment within LGBT communities.