Re: Trust issues from EX
She sounds like a narcissist, and they are narcissists with everyone...their parents, their kids, their siblings, their lovers, their exes, their spouses, etc. I don't have kids and have never been married, but ...my advice would be to not discuss anything with her anymore, relating to 'how' to better parent. It is falling on deaf ears, because she simply doesn't care. If she cared, your son would be brushing his teeth and not watched 'Saw.' She doesn't care because she is a narcissist, and the only way to deal with a narcissist, is to not deal with them. Your best path to take is to just discuss only things that have to do with making plans, and arrangements...and then, when you are with your kids, be the best dad you can be. You can't make up for her crappy parenting, but you can be there for them. It is sad that she sucks as a mom, but it is what it is. I wouldn't keep contacting her, and discussing things with her...because she doesn't care. There won't be this light bulb moment that she has over your ''talks'' with her...it won't happen, because narcissists don't self reflect.
Sorry you're in such a position, but just work on taking care of your kids and you...and deal with her very sparingly.