BlackSilver, consider this...
In the group I play with, we are all very good friends and get along pretty well. We would not play together, if we didn't. Every week, before the game starts, may wife and I cook dinner for whoever wants to show up early, and we sit, eat, drink and chat about what's going on in life. Sometimes we all get together to watch a movie, or have a barbecue or whatever.
However, we are under no delusions that the D&D game is more important than anything else going on in our lives. And while we all enjoy a few hours of gaming everyweek, we also are under no delusion that D&D is the sole basis of our friendships. We treat our RPGing as the geek equivalent of a weekly poker game.
In the last year or so, we've "kicked out" two players, and one left of his own accord. It happened because real life was interfering with their attendence to the point where keeping them around was simply too much trouble.
Each one of them was told, "It's not working. We're going to look for someone else to play in your place. Take time off from the game, and do what you need to do. You've got our phone numbers and you know where we live, we'll be here if you need us. If things get straightened out, let us know, you'll always be welcome in our game."
We've kept in touch with all of them, and get together with them when we can. One of them rejoined the game for a year, only to leave again.
And sometimes, just sometimes... People are jerks who are no fun to play with.
Remember, roleplaying games are just that... games. People can be friends without them. Don't fall prey to the
Five Geek Social Fallacies.
In this situation, if I was the GM, I'd tell the guy straight... "Look, we're good friends, but you never show up for the game. When you do show up, you act like a jerk and you ruin everyone's fun. If you really want to play, shape up and play. If you don't really want to play, don't. We can always go see a movie next Friday instead. Alright?"