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Demi Lovato arrived at the Teen Choice Awards in a sexy white Elisabetta Franchi dress, and when it was time for her to perform "Really Don’t Care" with Cher Lloyd, she changed into a rock 'n roll-inspired black Moschino number. Talk about a night and day transformation!

Demi was nominated for Choice Twin, Choice Summer Music Star Female and Choice Smile; and her hit “Really Don’t Care” was nominated for Choice Love Song, Choice Break Up Song, and Choice Summer Song. Demi won for Choice Summer Song and Choice Female Summer Music Star, and though she kept her speech short and sweet (unlike Selena Gomez's rambly and emotional one), it was quite inspiring.

"Thank you guys so much, this is amazing, and I dedicate this not only to my fans, also Cher Lloyd because we did this song together and she's amazing," she told the Shrine Auditorium audience. "Instead of just getting up here and saying a speech, each one of you deserves to live a happy and healthy, incredible life." Awww!

Check out their performance video below!