CC, You could ask, but he may not be able to tell you why he's behaving the way he is. It could be the holidays, it could be that he senses you are distancing yourself from his antics, he could be lonely or it could be all of the above.
If you do ask him, it might make him think about what he's doing and he could very well cease the "asking you out on a date".
If I were you, I'd accept him for who he is today and if you want to go out w/him, go, treat him as an old high school classmate that's come to town, keep the expectations at zero and have some fun. No one knows how they'll be tomorrow.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
