I never allow or put myself into a position for girls to do this to me so I don't know how to respond other than to......
SHOW ABSOLUTLY NO SYMPATHY FOR THEM.
That's right, when she comes to you to whine tell her that you should shake the guys hand that did this to her and that you should COME ALONG ON THEIR DATES TO TAKE NOTES.
Well, I'm not sure about the quality of the advice I just gave you taking that I don't know the situation, but experiment and have fun!!!
And don't be shy to tell the girl to fvck off at any given time and that you arn't going to take that whiney crap from her....