Breasts and Bodies

So I go to an all girls Catholic high school currently where we have male teachers and staff throughout the building. Whenever I go to our gym for class, we're always reprimanded for taking our skirts off before we're in the locker room (even though we all have shorts on underneath if we're doing that). So I went to the locker room to change shirts and got to thinking while I was in there: the only difference between my breasts and the breasts of the men here are that my breasts have more fat. Should I be faulted for that and made to cover up? And why should I be reprimanded for the possibility that a man likely twice my age may get "excited" by me taking my skirt off when there are shorts underneath? Yes, I realize it's also an issue of comfort for both parties and I'm not trying to suggest we should all be nudists or anything. I just think it's an interesting topic for discussion. What do you think? Should women's breasts be so sexualized even though they're mostly large because of fat? Or should they be considered the same way a man's breasts are? (I'll add in some scientific knowledge later)