The stars played peekaboo at the 2013 Billboard Music Awards last night! Celebrities including Jennifer Lopez, Emmy Rossum, and Taylor Swift all chose to wear designs that incorporated sheer elements (and all by the same designer, Zuhair Murad). Lopez’s gold skirt was see-through, Rossum’s side panels were covered in polka dots only, and Swift’s royal blue mini featured a crackle pattern that showed off her shoulders. But no one tried to do sheer quite like Once Upon a Time star Jennifer Morrison, who walked the carpet in a completely transparent gown (save for her skivvies) by Kristian Aadnevik. Click to see more fashion from the 2013 Billboard Music Awards.