This year's Billboard Music Awards went down in Las Vegas on Sunday night, and they did not disappoint. Between Britney Spears's nostalgic red carpet arrival [1] and epic performance of greatest hits and striking couples like Mila Kunis and Ashton Kutcher [2], plus a heartbreaking speech from Celine Dion [3], the evening was full of truly memorable moments — many of which you probably didn't see on TV. Scroll through for the best pictures of stars on their big night at the Billboard Awards.
Pictured: Rihanna [4]
Pictured: Ludacris, Ciara, Russell Wilson, and Eudoxie Mbouguiengue
Pictured: Ashton Kutcher [5], Wiz Khalifa, and Mark Cuban
Pictured: Demi Lovato [6] and Tove Lo
Pictured: Nick Jonas [7], Demi Lovato [8], and Wilmer Valderrama [9]
Pictured: Pink
Pictured: Gwen Stefani [10] and Blake Shelton
Pictured: Celine Dion
Pictured: Mila Kunis [11], Kristen Bell [12], and Kathryn Hahn
Pictured: Jessica Alba [13] and Mila Kunis [14]
Pictured: Rihanna [15]
Pictured: Ciara and Kelly Rowland [16]
Pictured: Zendaya [17] and Troye Sivan
Pictured: Celine Dion and René-Charles Angélil
Pictured: Ciara
Pictured: Britney Spears [18]
Pictured: Britney Spears [19]
Pictured: Gwen Stefani [20] and Blake Shelton
Pictured: Heidi Klum [21], Mila Kunis [22], Kristen Bell [23], and Kathryn Hahn
Pictured: Ludacris and Celine Dion
Pictured: Celine Dion
Pictured: Gwen Stefani [24] and Ciara
Pictured: Jamie Lynn Spears [25], Maddie Aldridge, and Lynne Spears
Pictured: Demi Lovato [26]
Pictured: Rihanna [27] and Idina Menzel
Pictured: Fifth Harmony