Safety pants, that is, longer boxers, prevent you from accidentally taking off your clothes when wearing a skirt. Safety pants are bigger and cover more than underwear, that is to say, you can't see much even if you take them off. You can wear it outside if you like, but not underwear. Pants to avoid running away. Wearing only one pair of underwear when wearing a short skirt is easy to run off, ensuring safety, and wearing another pair of safety pants can be avoided. This is also a function of leggings.