My ex wants me to meet his gf 😒

My ex wants me to meet his gf, but I'm not sure I'm ready to meet her. Here's a little back story... Me and my ex have been separated for almost 2yrs now, we don't co-parent anymore due to him losing his job, and moving to another city, plus I was the one who would take our LO to see him. We aren't even divorced yet, I've been trying to save up for it. I've basically been a single mom since, plus my parents help me with my LO. Fast forward a week ago he tells me he met someone and they plan on moving in together, now I know I have no control over who he sees but I'm annoyed and frustrated that he hasn't been a good father and his priority is a relationship rather than his kid. I guess I'm venting and asking if I should just meet her and get it over with? Or am I wrong on wanting to give it time till I'm ready to met her. I fell so rushed into something I don't want me and my son to be part of.