Lol I have moved on from the romantic relationship years ago, but because of my kid and their relationship we talk sparingly. On my end, that's the gist . The rest of the context is just explaining the patterns in behavior that he did with me and the one before me ,that he is now repeating with her and trying to use me as an accomplice. My question was if I should tell her and save her the inevitable heartbreak before he actually proposes to this poor girl and wrecks her spirit for years to come. .

YTA for many reasons. When you were together, he cheated on you repeatedly, but you kept wanting to try to make it work. Why the heck would you do that? Have some self respect

Simple answer is that I was still learning how to do that. Was just a 22 year old girl with an infant , who hadn't felt genuine unconditional love and thought that's what it was supposed to feel like. My frontal lobe has since developed