Morals the mother categorized me under an American Girl Who Just Opens Her Legs Up Which I felt Offensive With Other things behind it😤

My boyfriend's parents are Nigerian and he's an actual American but anyway. I told him his mom's a bitch and called her a cunt repeatedly and he warned me and totally blew me off the rest of the night. And I honestly feel like its not fair to me to get treated badly when she doesn't even know me to throw such assumptions and he's always defending her tho I understand it's his mother but what about what's right