Ask him. Apart from that, there is no sure way to find out somebody's sexuality. Some gay people do 'act gay,' but so do some straight people have effeminate behavior and many gay people don't 'act gay,' just as most straight people don't.
I think you can tell if people are gay. If a boy winks at another boy and waves they're gay, but only if the guy that winked is a complete stranger because family members, like the cousin, can wink at each other and you can't completely tell if he or she is gay!
You can't be sure and only the individual knows if he is gay. If a person decides to tell you they are gay, then you will know for sure. Otherwise, it's none of your business.
Gays are right next to you on the bus and others in the doctors office or even the doctor. Don't be afraid. They are just like you and me, they just love someone just like them which come to think of it we do that, too.
Some gays flaunt it and some don't so it would be very hard at times to tell if a person is gay. It's also not fair to the other person to ask if they are gay and you pretty much have to wait until they volunteer that information. Some guys that are gay come from all walks of life and can be muscular, rough and tough looking, while some gay men can be very effeminate. Does it really matter!
If you are in a straight relationship and are wondering about your boyfriend then he may be bisexual. Then if this is a concern to you ask, but be warned, if the person isn't gay or bisexual this remark could end your relationship.
Note: There are comments associated with this question. See the
discussion page
to add to the conversation.
You don't always know, sometimes they hide it or they don't act stereotypicaly gay. Some gay guys act feminine, for example talking in a high pitched voice or wearing feminine clothing. Some guys can...
Does he smile at you? Do you see him checking other guys' pecs, butts, or packages? Then he's gay, or the kind of straight man who will be flattered by being asked out.
----
There is no way to...