I am a gay man in his late forties who has a wonderful niece -- whom I'm very close to -- in her early thirties. She has had some very unfortunate relationships with men and been hurt very badly, and I don't know if she could take another defeat. She's fallen head over heads in love with a man she describes as a great guy. When I finally met him I was flabbergasted -- and deeply depressed for my niece's sake. I have seen this man many times -- yes, I am sure it was him -- cruising in local gay bars, even made out with him once a couple of years ago, and he is always inebriated. I have seen him neck with and pick up other men. I don't care if he's gay or bi, I don't want my niece to be devastated by marrying --yes, they are talking about marriage -- a man who may not be in touch with or honest about his true sexuality. He may continue to pursue men even after he's married. What on earth do I say to her? Bob.
The truth, I'm afraid. Men who want sex with men when they're very drunk want sex with men when they're sober, only they need to get drunk and lose their inhibitions before they can do so. It's the old bugaboo, internalized homophobia. You're right -- it doesn't matter if he identifies as gay, straight or bi, his future wife needs to know -- needs to know now -- about his possibly risky behavior, his lust for men, and what it may mean for their future, assuming any is possible.
There are so many ramifications to this. There are women who don't mind marrying gay/bi men (as bizarre as it sounds) generally for the same wrong reasons that gay/bi men often marry women. But every woman should be told beforehand -- hopefully by the man himself -- that he's gay/bi so that she can make an informed decision about whether or not to marry him. If he's essentially a gay man, he will not be happy in a straight marriage, and neither will your niece. Bi advocates say a bi man can be perfectly happy with, and faithful to, a woman (although there are thousands of men seeking male sex partners on gay dating sites who identify as "married and bi"), but this man sounds too conflicted to have any kind of realistic attitude toward his sexuality, and he probably hasn't fully accepted his homosexual feelings.
Don't tell your niece you once made out with him. I assume you don't have a "thing" for him as that will only complicate matters. That's not the issue in any case. The issue is that she thinks he's straight and he clearly isn't.
I would suggest sitting down and talking to him first. Don't wait until you run into him in another gay bar -- he'll be too drunk to hear you. Tell him you're aware of his nocturnal activities and you're not certain why he wants to marry your niece. Is he in love? Will she be his beard? What's going on? Tell him he has to tell her of his feelings for men or you'll tell her for him.
This isn't going to be easy as he sounds deeply closeted and repressed (except for when he's drinking) and he may be in such deep denial that he'll never be able to talk about it with you or anyone else in the light of day. Go slow, easy, be compassionate. If you get nowhere with him, you may have to be a real Dutch uncle with your niece. A marriage shouldn't start out with such a big lie between two people.
Get back to me and tell me how it goes.