Need advice! its a long story

Lo

We have been living together since august of 2017 and when we got together he had been out of a 7 year relationship for a year and a half. According to him she did him dirty. Eventually he told me he did her dirty too, so it was toxic and back and forth till they gave up. I dont comment on his past relationship because he was obviously with her for a long time for a reason. I have no reason to disrespect her. Well right before we got together we agreed to make amends with our exes ( at the time I had recently broke up with a guy of 6 years due to cheating).I thought it was a good idea I didnt want to leave a negative door open to our past. His ex got pregnant a few months after they broke up and got married once the baby was born. Once her mom found out we were dating she started commenting on our picturing saying things along the lines of him messaging her daughter still, how were bitter, He doesn't amount to the man shes with now and just rude comments for no reason out of nowhere. I never met this lady. I knew about the message he sent his ex because it was an apology for his past actions and congratulations on her baby. Eventually his ex wrote him back apologizing for her mom. Then they texted for the entire day and a half . I brushed it off because he said they were just catching up since they havent talked in a year. But he asked if he can add her on fb and i said no it made me uncomfortable. He added her anyways. I voiced my opinion and he deleted her . a few weeks later i noticed they were friends again and also noticed they still text. Not daily but twice a week or so. i noticed they added eachother on Snapchat a few months ago . They dont text on fb anymore just snapchat. Today he was showing me a video and it slid to his recent activity and they were chatting again on snapchat and he rushed to hide it. He told me he didnt want me speaking to my ex and out of respect I dont. Is it normal for your spouse to talk to their ex ? I find it odd its only on snapchat they text and he was so quick to hide it from me. Why do you think he thinks its okay for him to do something and I cant. I also have to need to speak to my ex. Am I overthinking this? I need some girl opinions 😭