You're right about the enabling. If HE wants to see the kids then he needs to make arrangements to see them. Don't go out of your way to do so. What you're going to find out is that while you're doing all this for him, he's going to be finding OW. Stop the cake eating.
You can definitely be nice to him and enjoyable to be around, but no favors.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.