DH and I have had a painful time this year watching our ds 13, whose buddy suddenly no longer wants to hang out with him. We live in a small town and while ds is involved in many activities, even goes to school part time and has no trouble getting along with kids at school, sports, etc, he just really wants someone to hang out with, especially on week-ends. Meanness is a huge problem too--ds has lots of self-confidence and doesn't let mean-spirited kids get to him, but he's lonely.
My younger son and daughter have more friends than they know what to do with. We're actually considering sending ds to boarding school just to get him around kids who are more like him!
So no advice here...but I feel your pain. Sigh...adolescence, thankfully, does not last forever.