At a family gathering about 3 months ago, while my almost 2-year-old boy was sitting down eating, my mother-in-law (60) crowded up to my son from behind his chair. She hovered over him from behind and grabbed his fork out of his left hand. Before she could make him switch hands, I gave her the Dikembe - I stuck my index finger at her and wagged it back and forth while saying NO! My MIL is deeply superstitious, and her reason was that being left-handed is bad luck. She let go of his hands, shot me a dirty look, and huffed away.

Am I the asshole for not giving a damn about her superstitions? - for context, we are from the same culture. Additionally, my parents are old enough to be my in-laws' parents. So I'm very familiar with her beliefs. Was I supposed to sit back and watch? Am I supposed to sit back and watch in the future? Forever?

Am I the asshole for pissing her off and not caring? Was I supposed to apologize? Should I bring it up and say I'm sorry for making her mad, and that it wasn't my intention?

Is it better that I suppress my feelings and thoughts and not have reactions whenever my MIL tries to force her beliefs on my sons?