How can I "party together" on Halo 3?

[The King in Yellow]

At My house = Me and a guest.
At Friends house = Just my friend

So from my end, when I'm in the matchmaking lobby, how can I prevent Halo from putting us and my friend on separate teams? Isn't there an option to "party together"?

 

[=) =) yasmin!]

You have to go to custom games and when your are there I would switch lobby yah sometimes you will get separated and if you don't want to get separated then play Team Slayer.