An abbreviation for 'Muff Over Mates'
Used to describe when a
friend has disbanded or stitched up their own group of
friends, to spend
time with his or her partner instead.
Paul: Hey, where's Jerome got to? He's supposed to be meeting us in an hour…
Alan: I don't think he's coming
man, he called to say he was seeing Kathy again
Paul:
Man, that
guy is such a M.O.M!