Inextinguished feelings for an ex-boyfriend.

My ex-boyfriend and I broke up four months ago. It was a mutual split, although one I had premeditated a couple weeks prior to having gone through with it. He had been in the process of applying to med school and that more or less consumed both of our lives due to the resulting stress he was always feeling. Even though we did not date from the months of November through February, we were sexually involved 4 times during that period.

He only recently (as in last week) disclosed to me that he had been "talking" to a guy who lives 3+ hours away in another state. Well it turns out they became Facebook official last weekend (I saw this before I ultimately deleted him as a friend; this new guy has plastered himself all over my ex's wall). The thing is, we were last (mutually) involved Tuesday of last week. We got into a fight last Thursday in which, feeling depressed, I called him and then later went over to his house to talk to him. I told him I still loved him. Of course then I didn't realize the guy from out-of-state was on his way to visit for the weekend. I bumped into him on the way out and it was very awkward. My ex was very upset.

I'm not certain if I'm over him, or if he is over me. I still love him, that much is certain, and part of me even thinks I want him back (as self-degrading as it may or may not sound). One thing about him is that he suffers from depression and gets lonely quite easily, which often led to near-sleepless nights of me trying to comfort him. I was very surprised when he told me he was considering pursuing a long-distance relationship. I don't know how far ahead he is looking. Also bear in mind that he started dating me a month after his previous relationship ended, but he had enough understanding/respect for that ex not to announce it on Facebook for several months after the fact.

I am planning a karaoke dinner out in the town next week in which I will be inviting mutual friends. I would like to invite my ex (and even his new boyfriend) but don't know how wise it would be. Part of me thinks I'll get up on the mic and tell him I still love him in front of the whole restaurant - this sounds refreshingly romantic but could also be incredibly stupid. I guess I just don't know what I want. I have so many good memories (in spite of the bad ones) with this man that I would like him to remain a part of my life in some capacity. We were together for over a year, my longest relationship and his as well. What do you guys recommend?