I'm exactly the same with my in-laws. They do very little wrong, but their stance towards things very similar to your balloon incident really annoys me. One of them recently rang one of those psycho whores to get some help locating their lost keys. FFS. I have literally zero tolerance for their backwards ways.
Sounds familiar. My mom, sister, girlfriend, girlfriend's sister and girlfriend's mom all went to see that Sally Morgan a few years back, I find it hard to keep my mouth shut.