Photo: Kevin Mazur//Getty Images for AEG

Los Angeles can check off Sabrina Carpenter singing with Christina Aguilera from their Christmas list. During Friday night’s Short n’ Sweet concert at the Crypto.com Arena, Aguilera sang “Ain’t No Other Man” and “What a Girl Wants” with Carpenter, likely as a consolidation prize for entering a place called Crypto.com Arena. Aguilera came on stage wearing knee-high boots that were almost as sparkly and tall as Carpenter, and the two started hammering out the songs. Last month, the two recorded a duet of “What a Girl Wants” for Spotify; it was a huge milestone for Carpenter, as she previously said Aguilera was the first artist she fell in love with. And after scoring six Grammy nominations last week, this is just proof that this is Miss Polly Pocket’s world and we’re just living in it.