The friendship-turned-rivalry-turned-Twiter-respect between Christina Aguilera and Britney Spears is well documented. So it really shouldn't surprise anyone that Aguilera has a killer impression of Ms. Spears locked and loaded at all times.
But still. On the Tonight Show Monday night (Feb. 23), Aguilera delighted the crowd with her singing impression during a round of "Wheel of Musical Impressions." If you've ever wondered what Spears sounds like singing "This Little Piggy," well, Jimmy Fallon and Co. are here to help you out. (Side note: Fallon asking Aguilera "You know Britney, right?" is the silliest thing he's ever said.)