Green’s Dictionary of Slang

(W.I.) a woman who enjoys the favours (material and otherwise) of her wealthy lover; also in homosexual use.

1971		F. Hilaire Thanatos 165: [in homosexual use] ‘Come on, honey,’ he was saying in baby talk. ‘Come on, daddy’s ’ittle boopsy.’.
1996		Allsopp Dict. Carib. Eng. Usage 111/1: boopsie [...] A woman who receives and enjoys the favours of a boops.