AMA Stars Instagram Who They Forgot to Thank

7 View Slideshow ⟶
The American Music Awards' biggest stars let loose at ET's exclusive Instagram lounge Sunday night, where some got the opportunity to thank the people they forgot in their acceptance speech! Click to see them adorably make use of their second chance, plus see more cool candids from the InstaLounge!

First up is Ariana Grande, who besides stunning audiences with her retro-style performance of Tattooed Heart, picked up the Favorite New Artist award. Her "nonna and Grandpa" got a big thank-you from the singer backstage.