What to do when a guy desperately wants a relationship and you don't?

You tell him that if he cannot accept a basic, platonic friendship and he keeps pressuring you for more that you will not be able to stay in touch with him. Simple.
If you have been very clear and consistent with your rebuffs, then he is now trying to guilt and manipulate you. Red flag behavior. Healthy people accept “no” as a complete sentence.

Just say no. Print it on cards. Hire a plane to pull a banner.

Have the town crier announce it.

Spend huge amounts of time and energy repeating yourself.

Or, not.

I tell him I’m married. To a woman.

Tell him the answer is no, and the reason doesn’t matter. Tell him, “I. DO. NOT. WANT. TO. BE. IN. A. RELATIONSHIP. WITH. YOU.” And that, if he can’t accept that, you can’t be friends or even speak to him.

I thought men were scared of rejection. This guy obviously has no problem acting pathetic and desperate just to get a date.

Be honest an tell the person how “YOU” feel an ask them to put the shoe on other foot!

I would tell this guy that he’s starting to reek of desperation, which broadcasts for miles. Needy, self-pitying men have no appeal whatsoever. If he keeps pushing himself into that mindset and acting the part, nobody will want to go out with him.

Let’s not judge the guy. He likes you a lot. That’s fine. Your job is to communicate clearly with him.

Tell him that you haven’t been being very strong in your “no” because you don’t like being mean, but it seems clear he is not hearing you when you are nice, so you’re afraid you have to say it very clearly.

NO! I do not want to be in a relationship. Please do not contact me again. I’m sorry the nice route didn’t work. Now do not contact me again. I do not want to be mean to you, but I will if you force me to.

Women are often trained to be nice from an early age, and so it can be difficult for you to say no. Especially to someone’s face. But you have to. If you don’t, guys will often interpret that as you not knowing what you really want, which means they have a chance. In order to cut that off, you have to be much stronger than you may be comfortable with. I’m sorry it’s like this, but this is the way it often is.

Also, having been one of those guys, you should know that you are doing him a favor by being strong. Not being strong keeps his hopes up and draws out the agony of hoping for you. By being strong and clear, you may hurt him up front, but in the long run you save him, and yourself, a lot of pain.

I’d be weary of a person who doesn’t get the message. Just saying.

Stop being nice.

Tell him that you are tired of talking about it. You simply aren’t interested in him that way. Then cut off any friendship. That will bring up fewer occasions where he can badger you.

Just be very firm and say ‘no’. It may be you have to stop having anything to do with him if he can’t accept your decision.

If he became very bothersome, and you feel unsafe or that his attention goes beyond what could be considered normal, speak to the police. I am just considering the potential for stalking and the like.

Time to have him solve a simple anagram, “shut will the up you please fuck?!?”

Thanks everyone! Great answers all around. Thing is, I’ve known this guy for a really long time, and he’s a good friend. I just told him very bluntly that I’m sorry, but I do not want a relationship. I also have him so he doesn’t see when I’m online on FB (that’s how he usually contacts me and sends me messages… lots of them), although I think it will be some time before he will move on even though I keep telling him… Hopefully this will resolve soon.

Restraining order

I would probably avoid him and ignore him