The unfortunate habit of spewing thoughtless, seemingly random, usually inappropriate and/or profane thoughts via text message. Often, these sentiments may be true, but fall under the category of "OK to think, but not to say out loud."
Texter: Your mom's ass is f#%$in tight in those jeans!!!
Textee: Dude. They have meds for textourettes now. Talk to your doctor.
A condition similar to Coprolalia (the condition which causes one to shout obscenities involuntarily, often confused with Tourette's syndrome) brought on temporarily by making mistakes while playing Tetris.
Guy: So how did you like the movie babe?
Girl: It was the sweetest movie ive ever seen! BOOOO-HOOO
Guy: Honey i think your tearettes syndrome is flaring up again.