Am I the asshole for being salty about a kid gendering tables?

I 12( (non-binary) go to a fancy school and at the beginning of the year I offered to help with kindergarten because 6th grade is in elementary school still. So I joined and have been helping for months but in one of the classes I was sitting at the table and this kid came over and started making kids sit at a certain table and he told me “this is the boys table, that’s the girls table it’s the only thing that should be a rule in this school, the girls in this class shouldn’t be friends with boys.” I was so mad and all the kids where already sitting down so I told this kid and went in the middle of the table “for girls” and made him sit there and he was on the wall outside for a week. But my friend told me I’m a asshole. So am I the asshole?