IBBT

IBBT - Itty Bitty Back Titties - Back fat that looks like breasts, often accompanied by a large or small amount of cleavage. IBBT is often found on a larger woman's back and is caused by wearing clothing (tube tops) that are too small.

Husband: Maybe you should reconsider the small bikini top, it gives you IBBT. I'd stick with the extra large.

Wife: Fuck you!