UTBNB 

Up The Bum No Babies. Fucking a bird up the arse with the aim of not procreating. AKA Cornish Contraception.

I may be wrong, and this is based on pure speculation and not any hard facts, but I bet she takes it UTBNB.

UTBNB by Spam October 12, 2003

utbnr 

Up The Butt No Rubba!!! (thats rubber for those not familiar with a New England accent)

So then the poodle says, UTBNR!!!!!

utbnr by Figawi May 6, 2006

UTB=NB

A popular call prior to sculling or shotting alcohol.

Up The Bum... No babies

Loft glass in air

Person 1: Up the bum
Rest: No babies

Variation

Person 1: UTB
Rest: equals NB

UTB=NB

UTB=NB by Ryza May 9, 2006

UBNB

Up The Bum No Babies

UBNB

UBNB by derillio May 12, 2010