Well that's part of what makes me hesitant to label it as an addiction - he doesn't spend any "family" money. He's very controlled with his gambling budget.
Ummmm....you are married, and he's spending money gambling. That IS family money that could be used for the FAMILY. I also wouldn't be surprised if you found out there's a lot more money involved than you know. His behavior sounds very addictive. Have you run a credit check to see if he's got credit cards you don't know about?