VIDEO : What Did Christina Aguilera Say When She Saw Kylie Jenner's Halloween Costume?

Kylie Jenner's Halloween costume has Christina Aguilera's stamp of approval! On Sunday, the singer reacted to Kylie's Halloween costume, which was none other than a Dirrty-Era Christina costume. "YAASSSSS?..Killin it @kyliejenner," she wrote on Instagram alongside a photo of Kylie. "Yes to dirty 2016!! Get it girrrl!!!" Kylie went all-out with her Xtina costume that she wore Saturday night.