when someone eats their food in a manner that would induce vomiting from anyone unlucky enough to be near them at that time. especially people that get grease or sauce all over there face while eating. the more zits the more likely you are dealing with a true Thasty Mcnasty.
dude look at how he has more chicken on his face than in his mouth, he is pulling a thasty mcnasty.
by hookman13 July 07, 2010