Would you go back to court?

My ex and I have been divorced for two years now, but have shared custody and physical placement, so there is no child support exchanged. In that time, he has managed to father another child (he pays $600 in child support on that child), he bought a new truck 2 months ago that costs $500 a month, has had 4 different women living with him (the most recent has 3 kids that stay on and off). He has managed to ruin his credit with his crazy choices and now has decided to move back home with his parents to "save money for a house". His parents adopted 3 troubled kids. That is great, however these kids have been victimized, and I am in fear of my kids being around that on a daily basis. I still don't want a dime from him, just stability for my kids. The courts are so nutty these days, but do you think I have a chance in getting an adjusted order regarding placement until he gets more stabilized.