What are his intentions?

I would really appreciate some insight and perspective on this problem of mine.

This guy who I had a few dates with last year responded to my text to catch up with an enthusiastic yes. He also mentioned that he had a girlfriend and would have to ask her but that it ‘shouldn’t be too much of an issue’. I did not know about the girlfriend. Now I am wondering about his intentions. We did really like each other but had to stop seeing each other because it became a long-distance relationship. Now I am moving back to where he lives hence why I texted to catch up. I don’t understand why you would want to meet with an ex if you are happy in your relationship. I don’t want to hurt anyone by agreeing to meet. Should I meet with him bearing in mind that I would like to keep in touch (but under no circumstances get involved with his relationship!)?
We weren’t friends before (we dated) so I am confused as to what his intentions are?