This is one I'll never understand. A few people in my life are going through this same thing. A family member is head over heels crazy for someone who doesn't want to have a relationship beyond friendship. This person kindly, but firmly made that very clear. Still, my former in law can't let it go, and it's making them nuts.
Ethel and Fred are in a similar situation. For years it seemed that Ethel chased Fred, wanting desperately to make their relationship work and he seemed ambivalent at best. He said he cared, but his actions always showed that he didn't. Now the tide is turned and Fred is desperate to prove his love to Ethel and she can no longer see a future for them together. She hasn't said the word "Divorce", but she's danced around it in every way possible. I think she wants to leave the door open in case she has a change of heart...or maybe just saying it makes it too final right now and she's not ready to face the finality of the death of her marriage.
My X decided we were getting divorced. I heard about it from my former Father in Law in fact! Then once I moved forward and got my own place to live, a job, and the final straw being my X finding out I had been with another man...BAM, all he wanted was to get back together. When I refused he got...well, crazy. At one point I asked him, "X, why would you want me? I don't love you. I don't want to be married to you. We are not happy together." His reply? "I don't care if you're miserable every day for the rest of your life, you don't get to destroy what I built." NIIIICE.... wow those are the words every woman wants to hear when someone is trying to convince them to continue or renew a relationship.
Why do we do that? Why do we want people who clearly don't want us? Is it a part of that whole, wanting what we can't have mentality? The grass is always greener... all those sorts of things? I personally don't get it at all. I want to be wanted. I need to be wanted.
I've been ignored and it feels terrible. And I wasn't even chasing my X... it was more like two room mates, and it still hurt to be dismissed. I can't imagine chasing someone knowing they're not receptive. My ego couldn't handle it.
I don't know how to help Fred or the In Law with this one... I want to say the right things, but I don't understand the whole dynamic they have going on, and I don't want to make it worse. I don't think, "Dumb Ass... get over it, move on, he/she doesn't want to be with you!!!" is the best way to reach either of them. And honestly it's a good way to get punched in the mouth! So..since I have the subtlety of a sledge hammer I realize it is kinder to remain quiet... confused and quiet.... and just listen while they talk.
That's all I've got to offer.