But there are plenty of men who think they are straight but are actually bisexual, attracted to women most of the time, but sometimes interested in men.
Or who think they are straight but actually gay, interested in men 100% of the time. They assume that being heterosexual means having cool, unsatisfying relationships with women and passionate, intense same-sex "buddies."
You can help him figure it out. He -- and his family and friends -- will be a lot happier if he stops pretending.
Getting someone to acknowledge same-sex desire is not for the faint of heart. It might be a better idea to stick to guys who have already figured it out, who know that they're gay, or bisexual, or straight but curved a little around the edges.
But if you're determined, here are 10 simple steps to success
1. Define your goal. Why do you want him to figure it out? If your goal is sex or romance, be careful: after figuring it out, he will want to try everything the gay community has to offer, mostly things that don't concern you.
2. Judge the strength of his same-sex interests. Is he almost exclusively interested in men, or is his desire fleeting and trival? That is, could he live happily in a heterosexual relationship?
3. Judge the strength of his homophobia. Does he just have a few minor stereotypes about gay people, or is he seething with rage? Does he make homophobic jokes, or does he say "live and live"? If he's exceptionally homophobic, skip Step #4.
But assure him that you don't find him physically attractive. Even if you do. Straight guys are under the impression that every gay man wants to have sex with them, and may refuse all future contact unless you make it clear that you don't intend to gawk at him in the shower or grope him in the subway.
5. Introduce him to gay people. The biggest reason for not figuring it out is the belief that gay men in real life act like they do on tv: they squeal, flutter, gossip, leer, and discuss skin care products. He likes football and beer, so he must be straight. Introducing him to a variety of gay people, with a variety of behaviors and interests, will disconfirm him of that notion.
6. Introduce him to accepting heterosexuals. The second reason for not figuring it out is the belief that family and friends will reject him. Straight guys rarely read about or discuss gay rights, so they often believe that the world is far more homophobic than it really is. Introducing him to some straight people who aren't screaming bigots will disconfirm him of that notion.
7. Know your Bible. The third reason for not figuring it out is the belief that God hates gay people. There are five Biblical passages that have been used to justify homophobic hatred. Be ready to look them up and explain what they're really about. If he's particularly religious, have a list of pro-gay churches and religious groups available.
8. Introduce him to physical contact. The fourth reason for not figuring it out is the belief that masculine physical contact is creepy and icky. You can disconfirm him of that notion quite easily. Tell him that gay guys always hug -- it doesn't mean anything. Invite him to a party that's so crowded that you have to sit pressed together. Once you get past the barrier of physical contact, he's almost there.
Be prepared for some trauma some guys aren't thrilled by the news that they're gay. They may experience guilt, shame, anger, and all of the other baggage they got growing up homophobic. You may even have to point out some support groups for newly-out gay men.
10. It make take awhile. But hang in there -- he's got nothing to lose, and quite a lot to gain.
See also: Yuri Comes Out; and The Homophobic Thad Becomes a Male Stripper