What do you call a person who does not go out with his friends?

What do you call a person who does not go out with his friends because he thinks he is superior to them?

Solution 1:

I think the word you may be looking for is aloof, meaning "not friendly or forthcoming; cool and distant". [Websters]

Although James had many friends, he remained aloof from them and hardly ever socialized with them.

Edited to add: The word also carries the connotation of supercilious, which means "behaving or looking as though one thinks one is superior to others".

You could also simply say:

James remained aloof from his friends.

Solution 2:

Title of this question was a bit misleading. First thing that came to mind was that the person was introvert or even somehow socially constrained. If you are sure that the reason for this is that he thinks he is superior to his friends, he might be "snob" ( as Hellion already said ), "pretentious" or "haughty".

However as someone who prefers to stay home instead of going out with my friends, I'd like to point out that it is not necessarily person being smug, but merely one that avoids crowds, possibly a "homebody" in a good sense.

Solution 3:

Unsociable or antisocial maybe, if someone doesn't go out much at all (if he does go out, but not with his "friends", perhaps he's just changed his circle of friends).