Don't listen to DarkHunt, he hasn't a clue what he's on about.
There isn't a method of playing 2v2/1v2 in multiplayer yet, but you can do so in singleplayer by using this program.
"Call yourself alive? I promise you you'll be deafened by dust falling on the furniture,
you'll feel your eyebrows turning to two gashes, and your shoulder blades will ache for want of wings."