Ex boyfriend wants to be friends. What should I do?

I was in a 10 year relationship with a guy, and one day he told me that he wanted to break up. We had a home together and all our mutual friends. Within a flash, our relationship was over and my life was turned upside down.We were both early 30's at this point. I got left with the home and all the bills, while he took off and started a new life. We barely spoke, and did not hang out socially. Shortly after he broke up with the student, and started seeing someone else and they've been married for 5 years.Cut to now. He's been calling me nonstop wanting to talk. I finally talk with him today after blowing him off for several weeks. Now, I find out he's unhappy and wants to break off his new relationship. he wants us to hang out and be friends. I dont want to be here for him. I don't want him anywhere near, but when we chatted, I did miss him. I don't know what I should do. I will not get back together with him, since I'm in a relationship now. I don't want him to interfere, but I don't want to turn away a person who was part of my life for 10 years. What should I do?