I look bad?

I don't get it. I want to go to warped tour this year. I plan on going with 2 of my best guy friends, and my one friends cousin. So far that's all we know for sure who is going. My mom says it will look bad if I go with a group of guys. I don't get what she means. I think my other friend that's a girl is going, but she's still saying it would look bad. I would think that people would be less likely to mess wih us girls if we're with a bunch of guys. Why does she think it's bad for me to go with guys to warped tour?