The people who smile to one's face while repeatedly driving an invisible knife into the back(s) of one, or multiple people.
You: "Hey girl, what's up? How have you been?"
ClosetFoe: "totally awesome! I really miss you!"
You: " well, that's nice. We should get together and hang out."
*brief intermission as your phone call or text ends, while another begins with somebody else*
ClosetFoe: "like OMG... you'll never guess who I was just talking to! Guess what I found out??! That b***h brushed her hair!!!.... I know, right?! I know it's not much, but we can make it work!"