This is short for "Mouth Open, Mind Closed." It's used when dealing with people who constantly talk without listening. This trait is common amongst guidos. Customer service agents think it often when dealing with pushy, rude customers.
Dude 1: Say dude, wanna come to the party tonight?
Dude 2: I -
Dude 1 (interrupts): Great! I'll see you there!
Dude 2: But I can't go!
Dude 1: We're gonna have a great time there! That really hot blonde is gonna be there, and I'm counting on you to be my wing man!
Dude 2: Yuck, this dude is M.O.M.C.
Dude 2: I -
Dude 1 (interrupts): Great! I'll see you there!
Dude 2: But I can't go!
Dude 1: We're gonna have a great time there! That really hot blonde is gonna be there, and I'm counting on you to be my wing man!
Dude 2: Yuck, this dude is M.O.M.C.
by quamp March 8, 2014