This is one complicated problem, but the best thing to do is discuss how you feel with her. Never mind about the ex, etc. All she can do is say she doesn't feel that way about you and don't take it too personally. She probably hasn't straightened things out in her own life yet. Take it slow, but don't be afraid to speak your mind to her. Be patient.
Marcy
Yes i agree that's a good answer, tell her first and see how she feels about you, if it so happens that she likes you to then tell the other guy to back off. if she says she doesnt feel the same don't loose her just tell her that its cool to stay friends then, because being her best friend you will always be there for her, she'll turn to you for everything and its nice to have a guy like that. she might even change her mind about the way she feels.
If possible, yes, you should try your best to stop your friend from attacking another person. However, if your friend is attacked first then they will have to defend themselves.
Why should you do anything? A person's love life is their own business.
talk it out before you do anything
No. A person who cuts someone else is not a person to be around and this is really true if they hurt a friend. This person has a problem and the more involved you become with them the apt you are to be another person they will hurt.
Don't go out with a person unless you like him, because if this boy actually has feelings for the person, and the feeling isn't mutual, then imagine how crushed the boy will feel.
I think you should ditch your best friend and replace her with another person who won't betray your trust by dating your boyfriend. That's what you should do.
I think that if this person is a true friend your feeling for one another should surpass whatever you are going through.
I think you should follow you heart and decide if you like your friend or this person more!
You should try to be friends with him/her. And treat him/her with respect.
You should always keep the date with the first person that asked you. If your friend told you to save that particular date and it obviously happens to be on the same day as a wedding for a family friend then you should choose the first friend. Another solution, and depending how far apart the weddings are; you could attend the wedding ceremony of one and the reception of another.
screw their dog
absolutely nothing. don't worry about it