I'm really bad at recognizing gay or bi-guys as well, it's not just a problem older gay guys have. Especially since some jokingly touch each other in a sexual manner or say stuff to each other (again, jokingly) like they are a couple or at least lovers.
I was wondering about that, but a bit too timid(/lazy) to ask. Good to see that it isn't just me. It's.. a whole new world. *ba-dum-tsssh!*