Feeling Betrayed by Fiancée's Judgement of My Friends

I don’t have a huge group of friends, I’ve always been a wallflower mainly because of anxiety. Through out my teenage years my family would often scrutinize any friends I brought home claiming them weird or out there because my friends were different (lifestyles, sexuality, even just personality) when my family would make fun of me for my friends it often made my depression worse. Later when I got older and moved out on my own, I no longer had to worry about my family’s judgments. I’m engaged to be married now my fiancée is great however recently my little brother has moved in with us and while he’s been here I’ve had some friends stay over for a weekend and by the end of the weekend my brother had my fiancée convinced that my friends were strange and “wrong” I guess is the word. While I tried my best to ignore my brothers judgements the fact that my fiancée bought into those judgements hurt me deeply. Like he doesn’t trust me or my judgments of people I want in my life. I guess my question is, am I wrong in feeling like my fiancée threw me under the bus in this situation? Like he figured my little brother knew better and went along with what he said instead of trusting me to make good judgements. I know I shouldn’t care about this but I can’t help feeling betrayed on some level.