Broken friendship. Can I mend it?

It's been an awful long time for you to hold on to something that really upset you in the past. Chances are he is not as wrecked as you , otherwise he would have at least made an attempt to contact you. For some I think, being a friend is always being around you every day of the week. Communicating with him seems to be something you have to initiate. You already know he is having a casual and open relationship, and maybe that's how he sees your friendship. Just something casual, may or may not see you or speak with you. It's apparent that he doesn't feel the need to make a commitment let's say, to any particular person. He is just doing his thing, when he wants as he wants. Perhaps another chance meeting will come about and you will see him again and at least speak to him a little. You probably know where he frequents so make it a point to ocionaly go to the same place you first met. I'm sure you're not a stalker and if the friendship means as much to him as it does you, it will come back. We all meet a lot of people in our lives, hopefully, and sometimes it's just for a brief time and then someone else comes along and so on and so on. During those times, not everyone is going to like us inasmuch as we don't like everyone we meet. There must be alot of good qualities with this person that makes you want to keep in touch with him. I hope it works out for you either way. Keep being the good person you are and don't let this stop you from meeting other friends.