It's a start. I really think you need to lay down the law with the guy. Make him play the game by your rules.
You are a teacher. You deal with structure and lesson plans everyday. You mold the future with these children. Use that power and experience to mold your future. Make him follow an acceptable lesson plan. You teach these children about consequences if they don't follow the rules and do the work. Why cant you apply that to your husband. After all, we see that he is just a child anyway.
Come on, get that ruler out and whack him across the knuckles a few times to get his attention. If that doesn't work get the paddle out.