I have one best friend I knew since grade school, he is currently doing his time in the South Korean military. Second best friend I knew since middle school, he went to a different university which is a two hour drive away. I get international calls from the first one once a week, and I drive down on the weekend sometimes with the second friend to have a drink and hangout. It sucks how it turned out, but at least we are still in contact I guess. Other ones just dropped out, when I graduated high school only the friends who cared stuck by.
I've only two friends I've keep'd around sense high school. they get along, but one has express some negative feelings for the other. However, I know this mostly springs out of jealousy so I simply don't mention the other when I'm with him. We don't really hang out as a group so that issue hasn't come up.
I made the mistake of introducing two best "friends" of mine and in one month it went from it being me and friendA/ me and friendB to FriendA and FriendB. I w3as backstabbed so hardcore it wasn't even funny.... There's more that goes along with that story too..
But pretty much it always happens like that, so I learned early on not to have my friends meet each other.