If you had been dating a guy for a couple months and he was a great boyfriend, but a little closed off, and he finally fessed up that he was going through an incredibly complicated and difficult divorce, would you run or stay?
I wouldn’t do either. I’d meander.
It’s not great that he didn’t tell you up front about his divorce, but it’s possible his intentions were good. Maybe he likes you a lot, and didn’t want to scare you off with a mean ex-wife, or maybe he didn’t want to talk about something so personal until he was really sure he trusted you and had strong feelings for you and could confide in you.
So I wouldn’t run screaming in the other direction, but I wouldn’t sit around on Saturday night waiting for him to call. By throwing all your eggs in his recently-divorced basket, you could be setting yourself up for heartbreak in the future, especially if you’re the first and only person he dated since his wife. This could be good for you, though; you said he’s a great boyfriend, so just enjoy him as he is, take things slowly, and see what happens.