RitaZ. said:
You said that there is nothing physical going on, but I think it's odd for "just friends" to sleep over at each other's homes on a regular basis.

Your "friendship" is definitely unconventional.
Time to cut ties, unless you are getting something out of this unusual arrangement. Good luck!
And
MrsPete said:
I think you're lying to yourself. If you really want to meet someone else and pursue marriage, you won't do it sleeping over at your ex-boyfriend's house (sex or no sex). Meeting for lunch = guy friend. Sleeping over at his house (again, sex or no sex) = more than a friend, potential for more than a friend, or at least interest from one of you.
Actually, I totally buy what the OP is doing. I dated a guy my senior year in high school for about a year. He broke up with me and we stayed friends. A year after breaking up he moved about 600 miles away. About twice a year I'd go up and see him and stay at his place for a long weekend. Seperate bedrooms!

We'd hang out and have fun, then I'd fly home. Once or twice a year, he'd come and visit me, stay at my place (again, seperate bedrooms) and we'd go out and see all our old friends from high school.
All the while, after the break up, I'm dating other people and eventually meet and marry my now DH. My ex stood up in my wedding last fall, and he's comming out to visit us in August. DH and I were going to plan a trip to see him over the winter, but he may be moving again so that's on hold until he knows what's going on.
People can break up and really stay friends, and "friends" is all it really is, nothing more. Sure, it happens that one person may still have hopes that the other will "see that they are made for each other" and they'll get back together. That may even be the case more often than not, who knows! But "just friends" can and does happen, I'm living proof!
Anyway, to the OP. While I totally get the friendship, until he gets whatever it is with the ex straightened out, I'd stay away and limit contact to phone and e-mail (and get your phone number "unpublished" by the the phone company, they are prohibted from giving out your address or phone number to anyone, including crazy ex-girlfriends telemarketers!

).