Our teenage son (17) likes this girl, but he allegedly doesn't have chances with her (*). While we do think that this is something he has to deal with himself, it did affect his mood visibly over the past few days. He's less happy and optimistic than he normally is, and it's rather sad to see this. We haven't really said much to him about it because we are not sure what to say/do: saying the wrong things isn't going to make it better.
So what should we do? Should we do anything, or let him deal with this himself?
(*) Based on some answer comments, I think I phrased this a bit confusing (non-native speaker here!). While the girl didn't flat-out reject him (i.e. saying "no"), he did approach her but her reaction wasn't the most 'open' one, if that makes sense. Basically she tried to avoid him most of the time and didn't feel much like conversation with him. So the problem isn't that our son doesn't know how to approach her.
To answer the "where do you live?" question: West-Europe.