Green’s Dictionary of Slang

little man n.

1. the penis.

[[UK]‘Bumper Allnight. Esquire’ Honest Fellow 9: And whilst his Homunculus [Lat. ‘little man’] throbs, / She asks — What’s the price now of fish?].
[US]Maledicta IV:2 (Winter) 189: The reverse process of this [...] depersonification of the penis is its personification [...] as little man, foreman, him.
[US]K. Shea ‘Having Chiqui’ in ThugLit July-Aug. [ebook] ‘[Y]ou blew your wad before you could even get your pathetic little man in the show’.

2. see lemac n.