You've always thought your boyfriend was straight, but now you're starting to wonder if he's actually gay. While we know that sexual orientation is a spectrum, it's important to identify the signs so you can make an informed decision.
If you find out that he has a lot of male friends, there's a chance that he's a closet gay. The old adage that birds of the same feather flock together definitely applies here. He may also enjoy watching men in semi-clad situations, especially if they are his close friends.
Do you see him complimenting other guys or flirting with them? Guys don't do this with girls; it's usually only done between men. If he seems to like this behavior, then it could be a sign that he is more than just straight.
Another thing to look out for is whether he talks about his sexual preference. If he gets uncomfortable when you talk about homosexuality or bisexual relationships, then that's one of the clearest signs that he is a closet gay.
Another way to figure out if your boyfriend is gay is to ask him about his past experiences with males. You can't always trust what people tell you, so it's best to get as much information as possible from him. He might just say that he's never had a man-to-man experience, which is also fine. He might just be telling the truth, but if he isn't, then it might be time to start looking for new possibilities.