I hate my boyfriends son and I think he has a mental illness

When I was in San Diego in the Navy, I had met this woman named Diane. Her husband was over seas for awhile,while I was not . Lol. Anyway, like you, I had a really hard time with her son. He wouldn't listen to anybody, he liked to do what he wanted when and how, etc. Way back there was a movie called "Trilogy of Terror" this little gremlins kind if thing was running around with a steak knife. But this critter wasn't much bigger than the knife. BUT anyway, one night her son Christopher, was in the kitchen and I heard him rambling thru the knife drawer. I go into kitchen and here is her son in a squatting position with a BIG ASS KNIFE in his hand, talking crazy shut and stabbing the knife over and over into the floor kind of like a sociopath, "hehehe I'm watching you" type of crazy shit. Ended up she took him to Dr. and he was diagnosed ADHD. I really don't know if him or his mom are even still alive or what happened to them. But I would see about having him checked for ADHD.