Christina Aguilera's son has a ''great'' singing voice.

The 'Genie in a Bottle' hitmaker wanted her kids, 11-year-old Max and four-year-old Summer - who she has with ex-husband Jordan Bratman and fiance Matthew Rutler respectively - to ''have a fun time'' at her 'Xperience' show at Zappos Theater in Las Vegas and knew her eldest child in particular would ''absorb'' everything about her concert because he is already ''very musical''.

Christina - whose residency in Sin City officially began on Friday (31.05.19) - told 'Extra': ''They showed up for the first time before opening night, I was like 'wahhh.'.

''They did [see the show but] not the first night...They saw the show the second night, my son absorbs everything, he is very musical, he actually has a great voice.

''When I see them here, I want to give them to have a fun time, I think they are very taken with all the visuals, the effects, confetti, all that good stuff. They enjoy it.''

While Christina's family weren't at her opening show, her friend Demi Lovato was in the audience and the 38-year-old star was thankful to have the support of the 'Skyscraper' hitmaker.

Asked how it was to have Demi there, she said: ''Amazing. It was so wonderful to have her support, her love and energy at the show, she's a blessing.''

Though she's only performed a small number of shows in her residency so far, the 'Dirrty' singer is feeling good about the concert series.

She said: ''We kicked it off. I'm so excited, awesome energy. It feels really good, already feels like a family.''

After attending Christina's show, Demi praised her pal for putting on a ''perfect'' concert.

She wrote on Instagram: ''The f***ing queen herself. A PERFECT, perfect show .. 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. Honored to call you a friend ... keep it up queen. Oh and EVERYONE should go see #TheXperience at @phvegas!!! (sic)''