Acronym for "The Shittest Tits Ever"
Commonly used as a code amongst males when describing a woman with a particularly horrible pair of breasts.
The code may also be used on a picture of the girl in question that she may have put up on a social networking site. The girl in question won't have a clue what the code means, but all guys will nod knowingly.
Chris: Man, have you seen Tara's tits?
Stefan: I know - TSTE.