Our Xs have a lot of similarities. They both seem to have this need to prove that they are more than capable of handling their situations until they actually do need a favor. They both perseverate on their looks. There is barely a time I don't see her that she doesn't ask something about her appearance. "Do my thighs look chunky?", "how old do I look to you?", "Does it seem like I've gained weight?"...yada yada yada. I've noticed that she's also spending on her appearance (no plastic surgery yet though) with various new clothes, dermabrasion, etc. It's uncanny how these things seem to go. Has your X got a tattoo yet?
Okay...now for the beating. I'm not sure how wise that was to bring up S5 staying overnight or even a few days with your Xs parents. Are they incapable of watching a child? I think you slipped into a controlling mode. What she does with S5 during her visitation is her business so long as it doesn't put him in harms way or otherwise adversely effect him. No wonder she got defensive.
The rest you handled well, although maybe a little defensively when she asked "why can't he stay with MIL?" It's okay to stand up for yourself, but saying "because I'm his father" sounds a little defensive to me. Perhaps it would have been better to have just said..."because I would like him to be with me that day." and leave it at that.
You are at a tough point right now. It probably has more to do with what your X is going through than about you. You're just a convenient scapegoat. Try to put yourself in her shoes if possible. Oh yeah, and when she said " I'm doing just fine financially and otherwise. I don't need your money." it might have been a nice time to validate. "I know you are. You've always been independent and good at taking care of things.", even though it probably is a lie.
Just my .02. I know exactly how easy it is to forget some of that stuff. I don't DB at all with my first X and I probably should if I want a better relationship.
Wes
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt