AITA For Yelling At My Sister In Law For Embarrassing My Wife?

I (28M) yelled at my sister in law (31F) for embarrassing my wife (27F). My wife is 6 months PP and was helping her sister get ready for a family get together. My wife was moving things around and picked up a bag of dog food and peed herself because of it. My sister in law who doesn’t have kids btw found it hilarious and decided to tell everybody about it. My wife was embarrassed about it and I confronted my sister in law saying she had no idea what my wife had been through and that if she knew, she wouldn’t be making fun of her.

Btw this isn’t the first time she’s tried to embarrass my wife