Slut shaming could be sent out due to two main reasons. Firstly, it could be because the girl could be showing explicit behaviour which exceeds out of the 'slut-shamers' perspection of expectations. Secondly... it could simply be the fact that the girl/women talks to guys. Yes this could provoke people to call them sluts due to the irregular form of jealousy. Even a small hint of rejection could push a guy to slut-shame a girl for not meeting his expectations. 

Slut shaming could happen anywhere, even at school. HighSchools have a high possibility of containing guys who slut-shame girls due to the fact that they are teenagers going through hormonal stages, this impacts the easy put-off of mood swings and anger. Rejection is common as many relationships are to be tried for, started, and ended. Teenagers seek for things they might have not done before, and relationships are something they havent handles quite responsibly, so leaving is a better option for girls when feeling uncomfortable and out of place, so it leaves them the option to leave/reject the boy. However, when this happens, boys usually cannot help but spread rude things avout the girl due to the simple fact that they cannot handle rejection, and this is where the foundation of slut-shaming starts.

This could effect the persons mental health to the point where the girl could feel as if to do unnecessary things, for example; not care for their privacy, staying silent, not speaking up for themselves, and worst for all, even ending it. Innocent girls who know/think they havent done anything would be in a more distraught state as the thought of them not doing anything allows them to wonder if everything they are doing is wrong. This could lead to a change in persona and characteristics (character change) which is not necessary.

To add on, an example of slut shaming in my school occured where i have witnessed it first hand. When i had seen a guy walk with multiple girls, i see that he is praised and applauded upon, but when i had walked with two of my guy friends, i had been called a slut to my face and behind my back. This really isnt ok as this is an example of double standards.

when looking into the future, stay away from the unwanted need of slut shaming because, remember, it's unnecessary and doesn't benifit. Anything.