Should I commit the robbery?

Ok, so there is this girl who I really like, but she is dating one of my good friends. I have liked her before they started dating, and I think I might have a chance with her. I know I could get her and my friend to break up, because she always asks me for advice and stuff with him, and she asked me if I knew if he chewed snuff, and I lied and told her I didn't know to cover up for him. He really does though, and she would definitely break up with him because she thinks its gross (I do too) and for lying to her, because he has been caught lying to her before and she said the next time she would break up with him. I could easily get them to break up and have a good chance getting with her. Is it wrong to do that to my friend though?