You know that scene in like, every werewolf movie ever made where the main character fights with everything they have to keep from turning into said werewolf?

That's me. I am the werewolf and my stepson is my full moon.  

I am trying so so hard not to become the mean step mom.  His behavior is literally violent and hateful. And when it isn't, he is creepily cheery and nice. Like when he smiles in that mood, I imagine it to be the same smile some poor stray cat would see before he kills it.