Life likes fucking with me.

[Supafly345]

If you think for a seconed that she isn't interested in you, chances are that you're right.
It is really painful, but you will be fine with it in a few days as long as you don't think about it too much.

Having never been in love I cannot properly map the best course when pertaining to your personal well-being. But ask your self, were you really in-love? Probably not.
Make sure you communicate with both her and the subject friend over the next week while trying to realise that it is Ok.

Of course, if you are really sure that you cannot live with this... go ahead and put fourth efforts to sabatoge any chances beween the two. "All's fair" after all.