whale tail tease 

A whale tail tease is someone, usually female but may also be a gay male, who deliberately wears his thong high enough and jeans low enough that others can see the color of the thong strap from the rear.

Jessica was a whale tail tease at the Mall last night. So déclassé and outré of her to do this!

whale tail tease by Sexy Limousine Liberal March 10, 2010