I just read it for the first time and I'm only on chapter 10 and the way the teacher acted, the fact that he showered and brushed his teeth many times, and how he felt like he can still escape while at the door - those are classical acts of someone suffering from sexual abuse.
I really like BDSM, not only in stories but irl as well and let me tell you - THIS IS NOT BDSM!!! This is sexual and physical abuse.
YOU CUTE ADORABLE BABIESS!! I LOVE YOU ε=ε=(ノ≧∇≦)ノ