I have a friend who jokes around about us running away together......

Well things have gotten worse in the last week. Persistent txt messages and even a confession that he is falling for me. It's doing my head in. I have stipulated that nothing is ever going to happen in that department, and it would not fix the problem anyway. This guy is a dear friend and I care for him dearly but that's it. How do I help and support him in trying to get his marriage back on track without either falling for him and making a fool out of myself, or getting into a situation I will regret later.
Should I back off and spend some time away for a bit?
Oh guys I am so confused, I did not know where else to ask?

I have mentioned it to my DH..... he understands, but I don't think he truly understands how I feel about this man.

I feel flattered that someone thinks I am an amazing women, but it's just the beginning of a lot of trouble isn't it?