Lori, you have told many a person on this forum that honesty is the best policy. So speak to your friend and tell her that her bum is big!
Be brutally frank with her about your feelings. If she truly is your friend, she will realise just how much she has offended you, and both of you will be able to attend the function feeling on top of the world.
If not, ...., then she probably doesn't deserve the award.
