I fear my friend is heading down a dark path. He has become very good friends -- or so he says -- with a much younger man who identifies as straight. My friend says his feelings for this younger man are strictly platonic, but the way he goes on about him it is very clear that he is smitten. I believe the young man is deeply conflicted and in any case will ultimately never allow any older gay man to become too close to him; the possibility of any real relationship is remote. I'm afraid my friend is going to get very hurt but I don't know what to do about it. George.
Sometimes, sadly, there isn't anything you can do about it. If he's in a deep denial about his true feelings for this young man -- or if he just won't talk about it honestly with you -- then there's not a lot you can do. I suspect that you've tried to draw him out on the subject, but he resists. Hopefully as he becomes ever more infatuated he'll turn to his friends for comfort and advice. The best thing you can probably do is be there for him when the ultimate letdown arrives. You're right that young, conflicted men often turn on the older gay men that have been there for them (sometimes out of their own needs, admittedly) and it's never very pretty. A good friend who will listen and help build up his self-esteem, reminding him that there are people who care about him even if his "beloved" does not, will provide some sort of comfort and support.
In the meantime, introduce him to some gay guys his own age who might take his mind off the conflicted pup. The easiest way to get over an infatuation is to meet someone new who can play back your feelings instead of constantly pining for the unattainable.