a large set of women’s breasts that perform a lively mating dance with the eyes of every man whos body is coursing with testosterone (A man need not be in eye-shot of such a spectacle to be effected as his...ur, umm…”divining rod” points the way like a compass to magnetic north.)
Dude: Scope those curvacious maidens. I’ll pounce the coal top with the bouncing betties. What’s your ruling on the blonde?
Wingman: The dewclaws are up.
(British) A girl's breasts. It is a play on words. A "bouncing betty" is a name for a certain type of booby trap. Accordingly, it refers to boobs - breasts.