I dont get the gay sensei story... can someone explain???

What is there to be confused about? He was attracted to his student and ended up having sex with him, even though he knew it's wrong.

His student is like drug for him... he knew that it was nos permited nd he also knew how controling his student is... also he knows is not correct to sleep with his student...

That is why he was afraid, he knew if he had sex with his student he will be addict to him, he is not strong enought yo fight against his feelongs for his student!!!