To ignore or not to ignore?

[sr9e2d7]

So Friday night he admitted to having a "thing" with this girl. He said nothing physical, but she was more of a symbol for the life he didn't have and the life he thought he wanted. She's young, goes out all the time, no responsibility. He said he doesn't want that life and wants his life back. I said we have a lot of work to do. Then tonight he texts me angry because his sister (my best friend) came to my Mother's Day. He's upset that she's "on my side". Then he said "it's making me rethink things", meaning the stuff he said about wanting to work things out with me. I'm wondering if he even meant what he said on Friday night about wanting to work things out or if he just said to distract me from getting so angry about the other girl. I just feel like he thinks this is a game. And I don't know what to do now. Do I just pretend that he didn't say anything about wanting to work it out and just see what his next move is??