The simplest answer I can give to such a complicated issue is that forcing things accomplishes nothing. If you've got to convince him to stick around, then he shouldn't be sticking around.

My best advice would be to simply let things play their natural course for a while. Drop any arguments you currently have, any issues you have with each other, and just hang out. If you can't manage that without fighting, then there are deeper issues than just what you've listed.

Also, in no way do I mean this to be offensive, but the fact that you immediately attempted to justify yourself after claiming to have been "led to" his conversations with said other, then odds are you're lying to us and yourself in some way.

Hope some of this helps, good luck.