I am a single gay man in my forties. A married couple I'll call "Dick and Jane" live on the same floor in my building. I am openly gay, so they both know all about me, and seem gay friendly. I got a certain "feeling" about Dick, who works at home (as I do) and seems to have one excuse after another to drop by my apartment virtually every afternoon, although lately I have taken to not answering the door. I am not interested in having sex with him or in getting into any kind of scene with this married closet queen, but I am convinced by his behavior, the way he looks at me, and many other things that he is attracted to me and is hoping to get it on. I am not at all into Woody Allen types (that's whom he resembles, only much younger), among other problems. It has reached the point where I'm almost ready to bar the door and tell his wife to put him on a leash! Buddy.
Does the wife look like Mia? How many kids have they adopted? Seriously, while it can be flattering to have someone kind of infatuated/hot for you, I don't think I would particularly care to have a married man who looks like Woody Allen ringing my door bell every afternoon either. [No offense to anyone who might look like Woody Allen. He's done all right for himself.]
I also say: Get right to the point. If you're absolutely convinced that this guy is sniffing around you in heat -- that he's not just a little lonely while (I assume) his wife is at the office -- then either never answer your door again or invite him in for some coffee and consolation. Tell him:
A.) You don't date married men.
B.) You don't date married men who look like Woody Allen. (Okay. Forget "B.")
C.) You don't date closet cases.
D.) You don't want to help him commit adultery.
E.) You'll have sex with him if he lets you have sex with his wife.
Okay -- I was so amused by your question that I'm getting a little silly. Here is my serious advice.
Definitely tell him that you think you know why he's coming around so often and (don't hurt his feelings) that you're extremely uncomfortable with the notion of fooling around with someone who's not only married but who lives down the hall with his wife. Jeez!
Ask him if he feels that he is or might be gay -- he might be a gay brother reaching out for understanding and striving for self-acceptance, and that may be why he's hanging around you -- an openly gay man -- so much. Tell him it's okay to be gay and recommend counseling at any gay center in your area. (And have him write Gay Dr. Bill. I'll set him "straight.")
If he's just a classic married homosexual or possibly bisexual who wants to cheat on his wife -- if he has zero gay identity and no interest in coming out -- tell him you'd rather he stay down on his end of the hall -- or you'll tell his wife to keep him on a fucking leash.
That oughta do it.