"You'd go into the bathroom when it was over and wash, telling yourself it meant nothing, hoping the water would be hot"

This quote is describing the moments after the girl would return from being sexually abused by her father. She would try to forget how horrible this was which can cause a lot of damage on someone. This also creates another dysfunctional relationship. The only time the girl and her father would interact would be when he was sexually harassing her. To do this a child is absolutely hurtful and it's awful that she couldn't do anything to stop it.