AITA am i the asshole for expecting my father to defend my mother
About 2 weeks ago, I went on a family vacation, and I was really bothered by how my brother-in-law (BIL) was disrespecting my mom, while my dad just laughed it off. They made fatphobic remarks, comparing her to a whale, and even made disgusting transphobic comments about her morning voice ("she sounds like a trans woman"). On top of that, my aunt was talking trash behind my back to my dad, saying she "runs her mouth too much."
When I told my dad that he needed to step up and defend my mom, he gaslit me, saying it wasn't what I thought and that I was "overthinking it" or getting it wrong. When I threw some subtle shade back at my BIL, my dad immediately chewed me out (for context: my BIL is rich and has connections ).
Am I in the wrong here? Is it messed up that I lost my respect for my dad and am furious with him over this, or am I the wrong one here ?