Honestly, you're gonna get sooo many opinions and suggestions on this topic that its gonna make your head spin and make you think that the person who posted the last msg is what you should do or believe, until the next person replies.
It's gonna make you doubt what you think you should do.
You're in a critical point in the relationship and you need to stay strong and put your foot down about what u need for him to do for you to even consider another chance.
And DO NOT ask him questions about it through an IM or a text.
You need to have a serious conversation w/ him, face to face so you can see his expressions, and have him answer every question you want answers to.
I myself don't agree w/ him still having ANY form of communication w/ her.
There should have never been any goodbyes or "I need to find out what happened, so lets meet". This is the woman he broke your vows w/ and he should have enough sense to
never talk to this woman again.
It doesn't make sense to have closure w/ someone who doesn't mean anything to you in the first place.
Or to have to repeat it over and over. And your name shouldn't be coming up in his reason to never speak to her again. You knowing should not be his reason to her.
He needs to keep it short and to the point so she gets it.
He obviously didn't make it clear if they still msg eachother. He shouldn't have responded to her wanting to see him again. Even a "No, its not gonna happen" is too much and gives her reason to think she can still msg him.
But like I said...opinions! and thats just mine.
You need to clear your head..make a list of the questions u need answers to,
take the baby to a sitter/relative so no distractions, and have him put everything on the table. The whole truth, because as his wife, friend and mother of his child, you deserve nothing less.