We have been married for 6 months and have a 4 month baby. One week before I had my son I found out my husband had been talking to his ex... I confronted him and he lied and blamed her, said she was bothering him, after what seemed like endless arguing I finally found her number and called her.. only to find out that he had also looked for her, turned out he had invited her to go out multiple times ( they actually met up once at the mall last sept.2018) he bought her a birthday gift and dropped it off at her house last nov.2018 and last asked her to meet up this past March .2019. Him and I got married in May of this year and they stopped taking 2 weeks after we got married, he did all this behind my back and his mom knew and never said a thing to me, he would hide his phone and keep it with him at all times which is why I got suspicious and decided to check his phone one day, he lied to me and what hurts the most is that he never told her I was pregnant and in some of the messages I found he complained about me having emotional distressed due to a past relationship. He even told her he missed her at times. I had a complicated pregnancy and my son and I almost died during labor. I feel like his second option, now I feel lost and broken due to the fact that he betrayed my trust when I was pregnant and needed him... he said he felt responsible for her and that he had to keep her around because he had been depressed in the past. Honestly idk if I should move on and ask him to leave or if I should stay? Idk who else’s to talk to. Please help.

Thank you