Dress codes are stupid but honestly a bra is underwear. If a boy had his pants sagging and you can see his boxers, he would get dress coded. If a girl was wearing a top where you can very visibly see her bra straps, it would be the same way. Schools are uptight, deal with it.
Favorite #Boxer. I'm the official greeter at our house. Welcome stranger: be nice or deal with me! I may attack you - in a variety of ways, one of which being jumping and slobbery kisses and the other, well, you don't want to know about the other!