Green’s Dictionary of Slang

1. (orig. US) a synon. for ass n.; esp. in phr. you bet your (sweet) bippy.

1968–73		Rowan and Martin’s Laugh-In [passim] You bet your sweet Bippy!
1970		J. Bouton Ball Four 105: A lot of guys would have told the trainer to shove the tea up his bippy.
1981		J. Sullivan ‘The Russians are Coming’ Only Fools and Horses [TV script] You bet your sweet bippy it won’t!
1989		(con. 1968) W.E. Merritt Where the Rivers Ran Backward 106: You bet your sweet bippy.
2001		Daily Howler 1 Oct. 🌐 Does the fate of Politically Incorrect really matter? You bet your sweet bippy it does.

2. the female breast, usu. in pl.; thus bippy top, a tight top that accentuates a woman’s breasts.

1998		‘The Swing Man’ at asstr.org 🌐 Carmen turned a lot of heads in a tight white miniskirt with a bippy top that left her stomach bare.
2003		posting at NoPC Forums 6 Mar. 🌐 I’d MUCH prefer to use my imagination while ogling some fine young thang in a bippy top than look at bare Euro tits framed by hairy armpits.
2006		W. Borden ‘La Petaudiere’ in Libido Mag. 🌐 I bite her bippies and teeth her titties. She confabulates my connies and I congratulate her cunny.
2009		posting to www.thephotoforum.com 7 Mar. 🌐 It’s truly a man’s world. The poor girl’s freezing her bippies off (whatever they are), while the guy’s all bundled up in a hood.