Taylor Swift is in a "full body sweat" after releasing her new single. The 24-year-old musician collaborated with fun. guitarist Jack Antonoff to record Out of the Woods, which they made available on iTunes today. It shot straight to number one, and it seems Jack and Taylor are as excited as their fans. The Shake It Off singer posted a text conversation between herself and Jack, in which he admitted to "literally" running into two walls while walking his dog with Lena Dunha