Demi Lovato Fangirls Over 'Queen' Christina Aguilera at Opening Night of Las Vegas Show

Christina Aguilera and Demi Lovato
Todd Williamson/NBC/NBCU Photo Bank via Getty Images

The 'Genie In a Bottle' crooner kicked off her Las Vegas residency, 'Xperience,' at Planet Hollywood Resort & Casino on Friday.

Demi Lovato adores Christina Aguilera!

The 26-year-old singer attended the "Genie In a Bottle" crooner's opening night of her Las Vegas residency, The Xperience, at the Zappos Theater inside Planet Hollywood Resort & Casino on Friday night -- and fangirled throughout the entire show.

"The f**king queen herself. A PERFECT, perfect show," Lovato wrote on her Instagram. "Couldn’t believe it was opening night because it was so smooth, flawless and sounded incredible. I was entertained the entire time and was so bummed when it was over until I was reunited with this beauty."

"I’m so so happy I got to hug you @xtina, haven’t seen you in concert since I was 14 and I can’t believe how much life has changed since then," she added. "Honored to call you a friend ? keep it up queen. Oh and EVERYONE should go see #TheXperience at @phvegas!!!"

Lovato also captured the show on her Instagram Story, singing along to Aguilera's greatest hits, dancing with her pals and screaming over how great the show was.

At one point, when Aguilera was singing "Reflection," Lovato captured herself crying with tears rolling down her face.

Aguilera and Lovato have supported and praised each other over the last year. The powerhouse duo worked together on the girl-power anthem "Fall in Line," and performed it together at last year's Billboard Awards.The two also received a GRAMMY nomination for their collaboration. 

"[She's] such an admirable young female who is figuring her own stuff out and knowing how to be strong and pull through," Aguilera said about Lovato in an interview in January. "Everybody has their own things they go through, and I just am so proud of her and I just think she’s so adorable and such a talent, such a fierce talent."

ET had sat down with Aguilera earlier this year, where she opened up about what fans can expect at the Vegas show, and her decision to commit to a residency.

"I was like, 'I can see why people are into the residency, because the travel and everything, picking up and tearing it up, putting it back up, all of it [is a lot of work]... to be sort of stationary, you get this great opportunity to build whatever fantasy and whatever kind of show you want," she said. 

Hear more in the video below.

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