Very old rhyming slang for tits
- has been used since the 18th Century in the UK.
"Look at the threepenny bits on that chick - they're popping out, man"
"I shot my wad all over her threepennys..."
A woman who has had several ejaculating penises in her mouth and now has breath that smells exclusively of cum.
Woman 1 : "God, my mouth feels like the bottom of a birdcage this morning"
Woman two: "I'm not suprised...you had a cock-a-too in it last night you old spunk breath"