Selena Gomez and Justin Bieber
Bryan Bedder/Getty; Steve Mack/FilmMagic
05/19/2013 at 10:00 AM EDT
Are Justin Bieber
and Selena Gomez
The on-again and off-again
couple was spotted at Cirque du Soleil's Love
together on Saturday at the Mirage in Las Vegas – just a day before place cards revealed
they may sit next to each other at Sunday's Billboard Music Awards.
Just before the show started, Bieber tried to inconspicuously enter the building, but someone noticed him and yelled his name, an onlooker tells PEOPLE.
As soon as the show began, the "Come and Get It"
singer was "nuzzling right into" Bieber, the source adds.
During the dimly-lit performance, Bieber wore sunglasses and a hat as the duo ate Mike & Ike and M&M candies with Sprite and apple juice.
– Mark Gray