Green’s Dictionary of Slang

(gay) a potential sexual conquest.

1972		B. Rodgers Queens’ Vernacular 194: TBH (Cape Town gay sl) can be made.
1973		(con. 1927–30) E. Williams Emlyn 27: He was amazed by my innocence [...] ‘Honey, you have the nerve to tell me you don’t know what “t.b.h.” means, but, cheri, [...] it means “to be had”, naturellement.’.
1973		M. Harris The Dilly Boys 82: The boys themselves are known in the homosexual world as rent, hustlers or TBH – ‘to be had.’.
1991		(ref. to 1930s) in Porter & Weeks Between the Acts 137: It wasn’t called gay in those days. One used to say, are you ‘so’? Or he’s comme ca, if you were higher up, or TBH (to be had).
1999		G. Seal Lingo 116: tbh is an abbreviation of to be had, meaning that someone is sexually available. ntbh means they are not.
2019		P. Baker Fabulosa 298/2: TBH 1. sexually available (to be had), 2. gay.