Oh, yes, younger music and clothes, uncontrolled spending, sportscar envy and immature, often drama-queen-type GF--that's all replay. Plus evasion, drinking, and hanging out with a younger crowd. And generally acting as though the spouse is a controlling mother-figure.
Under these circumstances, I'd suggest staying friendly to any contact he makes. But until he's ready to stop being the defiant teenager, he's likely to take any sort of "reaching out" from you as control. Show him how vibrant, well-adjusted and happy you are when you have contact. And don't worry about not having contact with him frequently: you're still in his thoughts. When he comes out of the depression, it'll be like Rip Van Winkle waking up: he'll be amazed by how much time has passed, and he'll remember more about your pre-MLC relationship than what followed.
Until then, ignore him. The BF you knew is in a coma and unreachable, so make the most of your time, your talent and your energy. The relationship he's had with you is abusive (you can check the symptoms of an abusive relationship for a checklist--including hiding a new relationship and thereby implying you were the problem). My H, as you point out, never left home; at some point I therefore had to face the question of why I'd been willing to live in an abusive relationship. That helped me get to the point where I was ready to move on without H. (Ironically, of course, that was the point when he wanted to recommit.) I suggest it might be useful for you to examine why part of you feels it should remain in an abusive relationship--not in a negative way, more in a now-that-I-get-this-about-myself-I-can-move-on sort of way.
