I split up with ex 3 years ago this December. We tried again 2 years ago but didn't work. We did bicker alot but over the past 2 years our relationship got better and we were in a good place friend wise and managed to do parent well. We used to go out with our DS the 3 of us and do things. This became more frequent april-june time. E.g. beach, restaurant, places for young kids. We would text each other alot about our son. It was never sexual but more friendly. But I did think oh this is going well. Maybe in the future things might work out as it seemed he had changed so much for the better. Then he tells me he is seeing someone. Then it turns into he took this girl on his holiday back in Feb which he lied about. Then it transpires he's been seeing her almost a year. He has been cagey with details about her and since he told me he has stopped doing stuff together and hardly speaks to me. I have a strong feeling his gf knew nothing about him doing stuff with us and he is worried I'll say something. I wouldn't but I know this is how he thinks.
When we were together he spoke to numerous women and I believe he cheated but don't have evidence on that. But I know for certain he was saying inappropriate things to women and was extremely secretive towards me. He has lied alot too.
I feel really upset atm like he's been so nice and we had a good friend relationship that looked hopeful to all of a sudden not talking to me and not doing stuff as a 3. Should I feel like this? I feel like he's been keeping me sweet while with her too.