text: Well, when I first read this I thought that she didn't do anything wrong because she told you that she liked him.  Well, I think she's a crappy best friend for lying to you about how she would never date him.  However, when you both found out that you liked him you should have a mature discussion, and told each other that you should both just get to know him better, and see who has the better chemistry.  I know best friends that dated the same guys (not at the same time) but it never bugged them because they were never real long-time relationships.  But if he hurts her or he tries to cheat on her with you, and you decide to go out with him then that would be really crappy on your part.  Even if you guys stopped being friends you'd be stupid to date a guy that was a jerk.  If you really think she's a good person then I would just talk to her about how next time she should just tell you, and don't be a bitch to her and let this ruin your friendship.  I wouldn't want her or that guy thinking you still like him so, if I were you I'd act like I already had a new crush.  On the other hand, if you question her character on a regular basis and she's just the best friend of the moment and not someone that you really connect with on a deep level then I would just expect things like this from her.  I would try to hang out with someone I trust more.