Fucking Rude

"Is it true that snakes mate all day long?"
 
One day, Won suddenly goes into heat at school due to a marking left by his ex-boyfriend without permission.
 
When he hurriedly hides in the bathroom, a man who appears to be a werewolf rudely confronts him, but in his desperate situation, Won promises to sleep with him and receives his help.
 
It turns out that he is not only Won's junior but also the illegitimate child of the center director who is monitoring Won...
 
"...Who are you really?"
 
"A crazy bastard who wanted to get involved with you."
 
What is the true identity of this man who seems to be lurking around Won?