Am I A Bad Person For Not Sticking Up For My Sister When My Brother In Law Mocked Her?

[Cindy1302]

I live with my mom. My sister and bil are staying with us for a couple of days. My sister was cooking dinner and one of the dials on the stove wouldn't turn. My bil whent over to help my sister and he started messing with it. My sister eventually started freaking out and was like "okay stop messing with it! I don't want to break it!". My bil was like "okay calm down" and as he was walking back to the living room, and as I was walking upstairs, he was like "sToP mEsSiNg WiTh It" in a high pitched tone. He was obviously mocking her. I grew up with my dad doing that to my mom, so i didn't think much of it, but is that bullying?

[Mozz71]

Probably worthy of a "Dude, that's not cool" more than anything else. Don't act further unless he keeps on doing it.

[Ringlet]

No, it doesn't mean you are a bad person - quite the opposite. You are showing how much you care because you are worried that your sister might be hurt by what your BIL did.
Try not to get upset by it. It seems to have reminded you of what your Dad used to do to your Mum but that is in the past.
Try to forget about it, and don't blame yourself.