I agree with the other two posts above.

Just because you have to work early in the morning doesn't mean that he ought to be going out to the bars with his buddies. Does he ever stay behind with you? Or is it a pretty common theme in your relationship? Like, he's out with his friends 3 or 4 nights a week?

I would take how often this occurs into mind. If he's going out often, I'd recommend a take me or leave me talk with him. If he goes out once a week, I'd tell him that him going regularly to bars worries me ~ can he do some other things with his buddies instead? Either way, get your feelings across to your bf. The clarity of how strongly I feel would depend upon what I'm getting out of the relationship now. {ie; Not getting much = point blank; I don't want to lose him = I'd word things carefully, so he doesn't go on the defense}