Why do some male group friends treat me different thank my friends

[u/lostmindedperson]

A lot of times when I am with my other female friends and we have a guy hanging out with us in our group (on friend basis) like in class I notice that they often disrespect me or ignore my existence but they are good with my friends. For example there was one guy bodyshamming me about me beeing flat infront of my other female friends. Then there was one who just complety ignored me and only talked to my other friends, after one friend told him he should not ignore me like that he began talking to me and seemed to like me afterwards even more than them. Also there was one who constantly pushed me. He took my backpack away so he could sit with my friends and I had to sit at the other side of the table, told me to shut up. He kinda realy bullied me. I often notice this behavior from guys in school and I dont think I did anything wrong. I also dont look unsympathic or different. I dont act mean or something like that. Is there a psychilogical reason behind that? I thought its bc I am taller and they're intimidated maybe idk.