b shirt
a t shirt that was worn by a fat person for so long the belly part has inflated and given the t shirt the shape of a b.
person 1: let's get six third pounder and four large fries for dinner.
person 2: dude now i get why you always wear b shirts
person 2: dude now i get why you always wear b shirts
b-shirt
A t-shirt you get free when every you buy a case of beer. Usually given away as a promotion.
Frat Guy One: Hey, did you get the beer?
Frat Guy Two: Yah, and a free b-shirt to go with it.
Frat Guy Two: Yah, and a free b-shirt to go with it.