I have a different take on this song. I think it's evil. Of course I don't blame the songwriter or Rhianna. I'm just talking about the song itself. The singer/narrator of the song almost sounds like she's the victim because she can't "get things right." However, she's a mean bitch, as she continues to pour salt in the wounds of her boyfriend. She knows that he knows she's a cheater, but he does nothing to stop it. There can be only one of two reasons why this is so, One, the boyfriend is so much in love, he overlooks the girl's nasty behavior because he's just not able to let her go. Two, he is a masochist and actually likes being cuckolded. In that case, the girl can't be blamed for bad behavior, because she is actually doing him a favor by playing into his fantasy. However, there is nothing in the song that implies that situation. So we'll assume the first scenario is true. In that case, the girl is totally selfish and evil. She knows that "it's killing him inside" but she continues to cheat and inflict physic pain. The decent thing to do would be to break off the relationship and leave the guy in peace. But she's not really a decent person.