Mu is another way of saying moo. It is a subsitution of saying any word or phrase. There can be an almost complete conversation of just this word.
Bob: So I hear you think Kristina is hot?
// Jim Shakes head as to say no.
Jim: Mu!
// Bob makes a look as to say "Why not?"
Bob: Mu?
// Jim makes a mater-of-factly look.
Jim: Mu!
// Bob makes an understanding look.
Bob: Mu.
Sex is turned into a total immoral action. Its all about having sex.... One day at my house a guy I know is dropped off at my house with a aluminum suitcase. I answered the door and of course he was excited to show me what was in the suitcase. A dildo that was a large rubber black object the size of a bulls penis.
pronounced as ehm-yoo. It's the abbreviation for "Murag Uyab" in Bisaya and it means "Like boyfriend/girlfriend". There's no commitment, loyalty or anything alike between the two, they just act like they're their significant other without the those.
person 1: hey, what's your relationship with that person?
person 2: oh, they're just my mu.
person 1: nice, so you can fuck with other people then?
person 2: yes but no and no but yes