taxes

so I need some advice on how some of you might handle this situation. My ex and I just recently split up. we have a one year old together. We've been doing great. he doesn't pay child support, I didn't file for it because I didn't see the need too. But my problem is we had an agreement that when we first split when he filed taxes he would claim our daughter and give me half of what he gets back. Well he just got his return of 2,000 about a month ago and I haven't seen a dime. I only knew he got it because he forgot that he put my number down and I got a text about it. after I said something about the text he confirmed that yes he did get that much but I completely forgot to mention our agreement. so I've been going over and over this. idk how to bring it up to him to ask him. He's a dick when It comes to this kind of thing. he will probably try and make me seem crazy or money hungry when I'm not if I was i would've filed for child support. I just wanted him to keep his end of the deal and honestly I knew he'd blow all the money on himself where as I'd put it in an account for our child or buy her a better carseat or something. how do I bring this up to him? How would you handle the situation?