Britney Spears [1] is taking her "Work, B**ch" attitude seriously during her Piece of Me residency in Las Vegas [2], and she showed off the fruits of her labor while out in LA on Monday. While taking a breather before her next show, she went out to lunch with her boyfriend, David Lucado, in a completely see-through shirt, revealing her black bra underneath. Everyone from Miley Cyrus [3] to Neil Patrick Harris [4] has been lining up [5] to see her new show, though her schedule may prevent her from making an appearance at Sunday's Grammys. Though she's not nominated for any awards, we'd love to see her at the show — it would be her second award season appearance this year after she won at the 2014 People's Choice Awards [6] earlier this month.