Attractive or best friend

I was with my ex for 13 years, slowly I felt like we were roommates and that there wasn't that attraction there anymore. We haven't been together for almost 2 years and I am dating someone else for a year now. The new guy is very attractive, our chemistry is great but he is not as sensitive or sweet as my ex, he's more of a mans man. He does care about me a lot and we want the same things but we are very different. Recently my ex has started talking to me. He is begging me to get back together, he cannot move on, he will do absolutely anything for me, and he has proven this. I obviously miss him since we were together for so long and are truly best friends, never fight, get along great but don't think those sexual feelings are there. Obviously we go well together since we haven't fought for the better part of 13 years. My new bf and I fight semi-often but we have worked a lot of things out and now things are really good. They say you should be with the one who would be holding your hand all the way if you had cancer, were sick. Not to say that my current bf wouldn't, he would. But my ex has this undying love for me and it's hard for me to walk away from that since I do still care about him. I know looks fade but if you don't wanna have sex with the person you're with?? That's not good either. Advice? What would you do?