Green’s Dictionary of Slang

cue n.1

(Aus./UK) the penis.

[Aus]Satirist & Sporting Chron. (Sydney) 11 Feb. 2/1: She was doing it heavy in the Theatre with one of the B—tts Brothers Clerks, B—yne, while while her husband was using the Cue with another partner in a room hard by.
[UK]Man of Pleasure’s Illus. Pocket-book n.p.: Most of these swell shakes are billiard players, only they pocket the cue when you cannon, and it is sure to win them the game.