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!

IBBT by fishy81 June 27, 2010

ibbt 

In before best threads.

<eXCeSS> hrm, a topic called "i figured out how to make homemade gummy worms"
<eXCeSS> HOLY SHIT HAHAHAAH IBBT
<prozium> Where'd my toothbrush go?

ibbt by Andrew February 9, 2005