I dated a guy for 6 years. We started dating when we were really young, and we were better off as friends, and we've remained friends ever since.
Right after we broke up, he started being stalked by his roommates girlfriend. She threatened to rape and kill him in his sleep. One night he woke up to her standing over him with a knife so he moved out. I'd always had a bad feeling about her, as she admitted to falsely accusing 3 men of rape. In short, this girl is a few quarters short of a dollar, if you catch my drift.
Well... fast forward to now (3 years later) and they started dating 2 weeks ago, and now he's moving in with her. I feel sick about it. How could you move in with someone that threatened to kill you.
I know he's an adult and can make his own decisions, but I'm actually worried about him and his safety.
So do I:
A) Tell him she's bloody f*cking nuts.

Tell him I think he's making a horrible mistake; or
C) Stay out of it.
Thanks guys!
UPDATE!
He asked me what I thought, I said lets meet for coffee and talk about it. That was returned with a: "Hi, this is his GIRLFRIEND. He will no longer be speaking to you. It's a little pathetic that you're trying to steal MY MAN from right under my nose. Not going to happen, slut. Contact him again and we'll be going to the police" So I guess there's nothing else to do, right? Hopefully he's okay.