Almost everyone! I would bet most guys have had at least one homosexual experience. Most of us during childhood, and mostly pretty tame stuff, but with shit like religion still poisoning people's minds, people still struggle with talking about it. Some folks get pretty fucked up mentally too. Guilt and fear has been the 1-2 punch that beat a lot of guys into the closet. Imagine living your whole life trying to hide that you're gay. That must be hell, but many men have done it. I'm not talking about sex here. I don't give a shit what kind of sex consenting adults engage in. It's all good! I'm talking about the emotional stuff. Nobody should be told who they are allowed to love. It's just sad!
Each passing generation becomes more liberal and accepting, so things have changed a little. Hopefully people get smarter too, and realize that the if human civilization is ever going to reach its full potential, religion is far from the moral high-ground.