Another question, although I'm not sure anyone will read it...

When he admitted he was feeling suicidal to me on Saturday he elaborated and said he'd actually pulled out his gun, sat on his bed, and thought about it. Should I tell his sisters or close friends about this? Problem is he really doesn't talk to anyone - he's shut himself off from most of the people in his life. I've only met his sisters once so I feel like this would be a HUGE invasion of his privacy, but I'm concerned.