Tznius isn’t decided by how many people of the opposite gender are looking at you. According to halacha you aren’t even supposed to be disrobed when changing into and out of your sleeping garments, but should do it under the covers of your bed. This isn’t because chazal were afraid somebody was peeping through your window, but because “m’lo kol haaretz Kvodo”. If anyone thinks having men not look is a solution, they are far from Daas Torah and completely mistaken.
The one thing I don’t get is how rabbeim in Yeshivas preach to their talmidim that wearing shorts in public is not tzniyus (unless engaging in an appropriate athletic or recreational activity that is normally done in shorts), but at the same time you can see seminary girls with their legs showing from the knee down – when everyone will often claim that girls have a higher standard for tzniyus than boys.