Gym clothes

You change into the sheer white shit ans tiny blue shorts that make up your gym uniform. You always hated how skimpy and revealing the clothes were, but riding the bus in them is way better than changing with the girls. There are no stalls, not even for the showers; and you never want to be seen nude. As a solution you ride the bus in your uniform and change in the bathroom after everyone leaves. The problem is that the boys have PE next and there's only one changing room, so you have to be careful.