I messaged him a long while after for closure. Other than that, we hardly ever speak. That's how it should be with ex's. He tried adding me on facebook, but I don't think I could ever let him that close into my personal space to where I could actually call him a friend.
Ex's are ex's for a reason, and most ex's aren't meant to be friends.
I have been contacted by exes and contacted some of my own too. In both cases it was because someone wanted to get back together. It's awkward to be the party that isn't interested, and once I knew what that felt like, I tried not to put others in that same position.