Would you let this person back into your life?

Last January I was going through a very rough patch in my life and that is when my best friend at the time, “Anthony,” decided he didn’t want to have anything to do with me anymore. It was a very sudden and unexpected thing, and it hurt me very badly. I was already in a very bad state and his maliciousness about it only made me feel a lot worse. Since that happened, I have temporarily withdrawn from school (his support at that time would have helped me stay there), gone home, and have met, dated, and become engaged to the person who is now my fiancee. Now, with the help of my fiancee and the passage of time, I have been able to forget the shock at Anthony’s betrayal and be happy with life again.
Anthony emailed me out of the blue a couple of days ago. He made a weak apology for the way he treated me but ultimately blamed his actions on his girlfriend, who apparently saw me as a threat and told him to stop talking to me (they were long distance dating and they’ve broken up). He said that he didn’t want to treat me the way he did but trusted his girlfriend so much that he was willing to do anything she told him. Apparently this break up is very recent, though, because I talked to his girlfriend a couple of weeks ago and he was visiting her in her state at the time.
So, get this. I mentioned in email to him that I’m engaged. His response to that was “it must be different for people who believe in divorce.” Now, I think I understand Anthony pretty well, and I think he was honestly trying to just be cute and does not understand that that was incredibly offensive to me. (Just because your relationship failed, doesn’t mean mine will.) I have wanted to respond back telling him that he’s an asshole, but have held my tongue because I know that he’s probably in a really rough spot right now, since in the two years he dated his girlfriend he became very emotionally attached to her. I’m pretty sure he’s depressed right now.
So, what would you do if this person, with whom you were once great buddies but had a nasty parting of ways, showed up in your life again?