At Prince William & Kate Middleton's Polo event in Santa Barbara this weekend, Joe Jonas debuted his latest lady friend. Her name is Karlie Kloss, and she's an 18-year-old model walking the runways of luxurious fashion houses such as Oscar De La Renta and Dior. The couple attended the pre-luncheon together, watched the polo game and later played around in a photo booth - making goofy faces and giving each other romantic gazes!

We have to give it to him, Joe sure knows how to pick them! She is absolutely gorgeous!