What goes on in Vegas most certainly will NOT stay in Vegas here!
Watch it go down (below)!!!
Does it get any better than this?!
While on the show, the 27-year-old helped Ellen pull one of her classic pranks as the songstress had DeGeneres in her ear telling her what to do and say as they pranked Jamba Juice workers!
As much fun as that was, the two celebs also sat down for a chat as the blonde beauty dished to Ellen about her frustrating performance at the Grammys, fame, her adorable son, and taking her first trip to Disneyland!
[Image via EllenTube.]