Overmasticating

Chewing loudly in order to irritate others. Overexaggerating the mastication (fancy word for chewing) process. Commonly performed with an open mouth and by a sassy or bitchy person.

1st girl- Eww stop chewing with your mouth open! Ya nasty! I can hear it!
2nd girl- *chews louder*
1st girl- ya bitch! Now you're just overmasticating!