GAYdar: How to know if someone is gay?

does it really matter if he is gay? i think if you are true friends, he will confide in you once he works it out.. it might just be, that he doesnt know himself.. and is trying to work it all out .. best thing you can do is just, support them and lend an ear. i dont know about a gaydar tho, i have many friends some gay and some not, and some of them i could have possibly picked as gay, but then again there is this one guy i dated and when i first met him i thought he was gay.. i was happy to find out he wasnt.. lol