Money, children (even before birth), everything.

When she was pregnant, I had to talk her off suicide multiple times after minor fights. Some of those times it was followed up with "but will you buy me X like I wanted"?

We owned over 50 strollers in less than 2 years. Many of them bought brand new, all sold with a loss. None were ever good enough. And then she fancied the same model she'd already bought and sold 5 times. Last time she got one of those in particular, I told her it would end our marriage. She laughed it off. We did not buy another stroller after that one and got divorced 2 months later or so. That one stroller was my final line in the sand, after hundreds of other reasons to break up. Sometimes you need a specific "if you do this after I've begged you not to, we're done" because it helps you realise how little respect they have for you.