Green’s Dictionary of Slang

1. a male homosexual; also attrib.

1955		C. Himes ‘Friends’ in Coll. Stories (1990) 269: Ah’m gonna tell ’n get ’em both locked up in de boy-girl company.
1963		J. Rechy City of Night 58: A queen boy-girl camped openly with a cop.
1971–2		C. Shafer ‘Catheads [...] and Cho-Cho Sticks’ in Abernethy Bounty of Texas (1990) 199: boy-gal, n. – a homosexual.
1972		(con. 1950s) D. Goines Whoreson 179: Others... fell in love with one of the boy-girls.
1999		N. Cohn Yes We Have No 100: A heart-stopping boygirl in black leather thighboots.

2. a lesbian.

1959

‘Sheldon Lord’ Strange Kind of Love 98: [A] Macdougal Street lesbian hole with boy-girls all over the place — dancing cheek-to-cheek and holding hands.