Having a relationship/baby with a guy who excessively coparents with his ex

I live with my boyfriend and have been with him for 2.5 years. We have a 1 year old daughter together. We both have kids from previous relationships. Through our whole relationships he has done things to make me not trust him but I stick with him for the sake of our daughter and he has told me numerous times he will change. Long story short he has previously flirted with his child's mother, he has sent her sexually explicit text msgs and he has even told her that he still loved and missed her and thinks about what could havve been. He dated his ex for 2 months and she got pregnant right away. As soon as she got pregnant she basically ended things with him and although she continued to fool around with him for a few months she got another boyfriend before their child was even born and basically strung him along. When he started seeing me it was under the notion that he had moved on. But he continued to try to get with her behind my back. He has on several occasions flirted/sent sexually explicit msgs to his ex and I have found out and I keep forgiving him. He claims that it gives him a rush and a high to act like that and he wants to see what she will say and that he doesnt know how to control himself. He always claims he is depressed since his other daughter cant have her mom and dad together and thinks about how his ex ruined his other child life. Although I keep forgiving him I have told him numerous times, to have a relationship with the child but he must keep minimal communication with his ex. Talk to the child on the phone and thats it ( his daughter is 3.5 years old that he has with his ex) and that when he visits his daughter he cant be going into the ex's apartment and there is no reason for him to be doing things alone with his ex and their child. He needs to keep them both separate. His ex msged him to tell him their daughter had a cold and that she was going to take her to the doctor ( ok) but then my BF wants to go over there and help with the doctors appt. If he was different it wouldnt be an issue, but every time he is around his ex he acts way too overly nice, complimenting her, flirting with her, he doesnt know how to be neutral, let alone all of the things he has said and done in the past 2.5 years. I feel like given his record, unless it is a dire emergency, not a little cold, there is no need for him to be there alone with her and the kid. She didnt even invite him, she was just letting him be aware of what she was doing. His ex always turns him down but lately she has been acting a little too nice then usual. She has always said she cant call or msg when she is at work and recently she has started msging my him and calling him to talk to him about their kid while she is at work. That doesnt make sense to me. And in the past he used to ask for pictures of his ex and daughter together and she always declined saying there was no need for him to have pictures of her too and recently she sent him a picture of her and their daughter. He doesnt think there is anything wrong with him going over to his ex house (he doesnt do it though but its just his opinion) and he doesnt think there is anything wrong with him doing activities with his ex just them ( he doesnt do it but it is his opinion) but I have a firm belief that if two people are not together, especially if they are both in new relationships, and especially if the guy has been inappropriate on numerous occasions then there is no reason for there to be excessive contact between the two. I feel like it is giving a false image to his other daughter. His daughter is 3.5 years old and already on a few occasions has questioned why her daddy was not in her mommys house. And his answer is always either doesnt answer and changes the topic or says "it is because he lives with (inserts my name).." The whole situation is just very stressful, it is hard being in a relationship with someone who has a child with another woman but it is even harder when he cant be trusted with his ex. I have a child with him and I want to make it work but it is near impossible to trust him. He wants to have with his ex and their daughter what me and him have but thats just crazy given the fact that they are not together. Im sorry but I believe that when you are in a new relationship and you have an ex things cannot be so friendly and close as if the two people were together, you cant always use the “Child card”. He is barely participant with our child since he has to work crazy hours but with his ex he wants her to see him as “super dad”. I get the fact that he wants a close relationship with oldest daughter but at the same time he cant expect that he is going to get all the perks as you get when you live with the mother of your child. There has to be boundaries when you have an ex and when you have a new relationship. I want to be with him for the sake of our child and I do love him but he just isn't trustworthy since he is obsessed with his ex. How can he stop his obsession with his ex if he constantly has to be exposed to her and see her and talk to her since they have a kid together?

Problem is that while you can believe whatever you want, he continues to pine for his ex AND he is not being a good partner to you and a good father to the child the two of you have together. Meanwhile, despite all your believing, you are the woman who is putting a roof over his head, putting food on his table, while he can't quite manage to pay his bills and you keep hoping that if you keep taking care of him, that somehow he will eventually appreciate you and be yours.... in effect you are trying to buy love. I hope you know it never works that way....right?

Like I said in your previous thread, you have serious issues with codependence that you should be looking into to help yourself out of this mess for good and hopefully into an actually healthy relationship in the future with someone who actually cares about you rather than keeps pining in your face about someone else...while you pay his bills.... Looking from the outside it....it's kind of mind boggling.

He won't change.

He has everything the way he wants it (save for having both you for convenience and his ex for excitement), but he sure is trying to have you both.

You can either accept it and continue, or NOT accept it and move on. There's no magic third option where he suddenly morphs into the man you wish he was.

Maybe you should get rid of him like his first baby-momma did and he'd dote on you like he does her?

I don't know about you, but I'd not be with someone who is still in love with someone else. Not even for my daughter because in the long run she'd end up far better off seeing her mother happy and content and LOVED by a new man in my life. I feel sorry for you to be honest.

Your problem isn't "excessive co parenting".... Your problem is a no Good man and your inability to see it and break it off with him.

Figure out how to co parent with him and move on. You need to let him go.

He isn't the problem at this point - you are.

You know he's in love with her and doesn't give a rat's behind about your feelings or the way you think things should be. (And I agree with your points of view, OP) He has showed you again and again that he's not going to change, and yet you continue to sweep it under the rug and hope that he sees the light. It's not going to happen, my friend.

So you are the problem, in the sense that you refuse to let go of a guy who just isn't a good partner to you and doesn't really love you. And I hate to tell you this, but his ex ever decides she wants to make a go of it with him, guess who's going to be left high and dry?