My boyfriends parents hate me?

We always learn from our mistakes. Next time don't get in the middle let the family handle it, don't respond to an ex-friend even if you think you are helping because people do strange things. Explain to the parents that you were lying to the ex-friend and that you are really sorry and you will not make that mistake again, let them know you were trying to help but you won't really thinking about how it would turned out. Let them know you didn't mean any harm and hopefully the family can start to heal and forgive you. Good Luck.