When one prevents another from being able to come to his/her house and eat his/her mother's food.
1.) Friend - "Sorry man, you can't come over, I have a ton of chores I need to get done"
You - "Dammit, you're mouth blocking me big time man, your mom's enchiladas are the best!"
2.) Chris' mom's food is the best, but he's always mouth-blocking me. Bastard.