Is it possible to successfully spare Benny when you encounter him at Caesar's?  I tried multiple times giving him the bobby pin/stealth boy combo, and he and I were immediately attacked.  I couldn't figure out whether it was possible to actually do this, and if not, why the developers set it up as an option.

You can simply talk to him and forgive him.

  Yes he can. If you let him bolt to Caesar's legion, and encounter him there you can op to free him. But you need to smoke everyone there, which is not easy at all. However, if you kill everyone there then he should be able to leave alive. I killed everyone in the tent, but not outside (don't ask me how) and he ran out and got killed by the dudes I didn't kill outside.

I forgave benny and he turned on me. I then reloaded save and shot his face off and wore his suit.

I turned him into a pile of ash. Ring-a-ding, motherfucker.

I wouldn't know, the moment I got Benny alone, I blew his goddamn head off.
 
Seriously, FUCK Benny.

I killed him, but I could only find a machete so I had to chop the poor bastard to death

I just met him in his room and blasted his face off with a sawed-off shotgun.

" @Mmmslash: Oh, I did. I DID fuck Benny. And then I killed him in his sleep. Black Widow FTW. "