Last night my son and I had to have what I call the Save Yourself talk. I've been giving my daughter this talk for years and it boils down to "when your friends are making bad choices, save yourself." Now, my daughter is a caring girl but my son is really a sensitive soul. And every time I tried to bring my point home he would try and offer an example where he could do the opposite of what I advised.
My last scenario: you're at a party and kids are drinking and your best friend decides to stay. Save yourself.
Son: Can I tell him we should leave?
Me: Yes, but if he makes a bad decision to stay you have to still leave.
Son: What if I see other people I know? Can I tell them they should leave?
Me: Well, yes. Once. But don't wait for anyone. You can't save the world. No one can.
Son: Everybody can, mom, but not everybody will.