Try to rile her up

"Oh calm down girl. That dress wasn't even that good, didn't show off enough of your curves and clevage. Besides, that's party was for boys and girls looking to have a good time, not a chick who's too much of a prude to get laid", you decide to say. Hopefully your dismissive and condescending tone will throw her off.

"Screw you! I am not one of those cheap whores or slutty girlfriends you got for that party!", she screams as she charges, pretty much all caution thrown to the wind.

You have definitely made her angry enough to be less cautious. Hopefully that will help enough.