It seems to me that you and Seamus have imagined quite a bit about what could happen if you contact D. - from friendship to sex to a relationship. But you don't even know if the number works or if he wants to be in touch with you again.
Originally Posted by Tonberry
While I'd be fine with some boundaries about not having sex with him, or not kissing him, or not meeting him at all, the idea of not contacting him when I'm finally in the same country hurts me a bit. I feel like I'll probably regret it if I don't. . . . There is chemistry between us . . .
chemistry between you. You don't know if the chemistry would still be there. How long has it been since you've seen him? Since you were in relationship?
Sadness won't kill you. Some people are only meant to be part of our lives for a specified time. Some people are best left as a part of the past. In my experience, reconnecting with old loves is a crap shoot, and often causes a mess. When you have old memories that you hold precious, it becomes hard to stay in the present and see the current situation clearly. Maybe Seamus's intuition is accurate and D. would not be good for you now.
You're back in France and feeling nostalgic. I can understand missing people you knew there, but the turmoil you expressed in your post makes me wonder if contacting D. again would be worth it. It's one thing if you looked up some old friends, and he just happened to be present, and it was impromptu and happened without planning. But you are already placing so much weight (expectation?) on what would happen if you got together, it just seems to me that you're projecting big complications on what's possible, and this is all coming out of a mental/intellectual kind of worrying or ruminating on all this -- rather than a passion or real organic feeling that being in touch with him again is what you want. Even so, I would be cautious if I were you.
This is a new stage of your life. Why not move on from thinking about D. and create new friendships and relationships while there? I know you asked for advice, and so I guess that would be mine, although I'm more inclined to just call it my opinion than advice.