Singer Demi Lovato fangirled over "queen" Christina Aguilera at the opening night of Las Vegas show. The 26-year-old singer attended the "Genie in a bottle" hitmaker's opening night of her Las Vegas residency, The Xperience, on Friday night -- and fangirled throughout the entire show, reports etonline.com.

"The 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."