A "friend" who uses, then betrays you. Backstabbers are also considered, full of them selves, bossy, annoying, and extremely bitchy.
Well, the other day a girl at my school was being such a know-it-all at our chemistry class. She kept on saying that she was smarter than everyone else, and she was bossy. Most of the answers she gave us were wrong. I talked to my other "friend" (Backstabber) and she told me to tell Know-It-All to fuck off, but I, being the nice person I am, didn't want to be mean so I didn't. Later that day Backstabber told Know-It-All what I said, and Other Loyal Good Friend whispered to me that Backstabber and Know-It-All were spreading rumors and telling lies about me. Backstabber deserves to be stabbed. Know-It-All needs to receive a nice, long email containing all of the insults, truths, and comments everyone wants to scream at her.
I am very sorry this example was so long.
I hope it was entertaining.