Louis, Liam, Ed, Taylor, Calvin, and Austin (Twitter) Taylor Swift knows how to have a good time. After stealing the show at the Billboard Music Awards, the "Bad Blood" singer and her pal Ed Sheeran threw a star-studded afterparty at the Nobu Villa at Nobu Hotel Caesars Palace in Las Vegas. The 25-year-old superstar let loose following her 8 big wins and it was all captured in the awesome photo booth — complete with costumes and props — on hand at the fete. Taylor's younger brother Austin, who graduated from Notre Dame over the weekend, posted the above shot on Twitter, writing, "Last night was a wild ride #DoneWithCollege." One Direction's Louis Tomlinson and Liam Payne got in on the fun, posing with Ed, Taylor, Calvin Harris, and Austin. In one shot, Swift and her DJ beau only have eyes for each other. Could her new romance have anything to do with why her ex Harry Styles skipped out on the soiree with his bandmates? "Ha...