I'm Her DUFF Arrow Designated Ugly Fat Friend Women's T-Shirt.
We all have one. It's the "Designated Ugly Fat Friend". You go to the bar, and this is the person you bring along to make yourself look good. She stands there next to you, and by default you're the cutest one in the bunch. Or at least not the ugliest.
And the fact is, no matter how hot you are, there is always the potential that you're somebody elses DUFF. So look around, and make sure you're not the DUFF.