There's like so many possibilities, and I've never heard the term before. When I search for "MMO", I get **** like "World of Warcraft" and stuff, so maybe what you meant was "MMORPG" which means "Massive Multiplayer Online Role-Playing Game", but I've never seen it abbreviated to just "Massive Multiplayer Onine": en.wikipedia.org/wiki/Massively_multiplayer_online_role-playing_game
I don't play video games or hang out with people who do. Well, I play Age of Empries I and some old SNES or N64 games sometimes, but I'm 30 and never got into LAN parties or whatever. WoW addiction was a big problem when I was in university and I had a hard time concentrating on my studies so I pretty much gave up gaming (except old SNES/N64 games to ease stress). I remember learning about MMORPG from that South Park episode.
Honestly all these new video games look cool, but I just don't have the time to invest in it. I work, I have a band, I make art, and I get drunk nearly every day and watch the sunset and talk to people outside about everything under the sun (I try to steer the conversations away from technology because I'm surrounded by it so often and would rather discuss something else).
One of my teammates is exactly like this, except that it's just his regular voice. He's in his 20's and has a full beard, and has a voice like a little flute.