Harry Styles and Millie Bobby Brown lived their best lives at Ariana Grande’s recent concert, and fans are here for it.

The 25-year-old singer and 15-year-old “Stranger Things” star were both in attendance at Grande’s show on Saturday at London’s O2 Arena as part of her Sweetener World Tour. Fans at the show spotted the two stars talking, singing, and dancing throughout the night, and shared the moments on Twitter.

Twitter user @rosiexwh, who goes by Rosie, was at the concert and shared videos and photos of Styles and Brown. She said that they were “five meters away” from where she was at the concert.

In one video, Styles and Brown were seen chatting and smiling as Grande performed "make up" from her "Thank U, Next" album.

They also danced during Grande's "Dangerous Woman."

https://twitter.com/rosiexwh/status/1162861571124731906?ref_src=twsrc%5Etfw

Styles posed for photos with a group of people.

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And he danced during "Break Free," which is from Grande's "My Everything" album.

https://twitter.com/rosiexwh/status/1162865544766341121?ref_src=twsrc%5Etfw

Read more: 9 times Harry Styles was a champion for the LGBTQ community

Speaking to INSIDER, Rosie told us that her sister was the first to notice Styles and she was "so shocked."

"I couldn't believe my eyes, it was so surreal, it probably took us a good five to 10 minutes before we actually believed it was actually him," Rosie said.

She went on to say that she felt as though she "won the jackpot" when she spotted Brown as well.

The 16-year-old fan added that she's been following Styles' career since around 2012 and started watching "Stranger Things" shortly after the first season was released.

According to Rosie, the stars spoke maybe for five minutes and "they were just mostly enjoying their time listening to Ariana perform and dancing along with their friends."

Another Twitter user, @emmaaaaat_, also shared a video of Styles and Brown's interaction at the concert.

And here's Styles dancing to "Into You" with a drink in his hand.

He seemed to enjoy "Dangerous Woman" a lot.

Fans who spotted the videos online couldn't get enough of the two stars enjoying themselves at Grande's show.

https://twitter.com/harryftkissy/status/1162858292235907076?ref_src=twsrc%5Etfwhttps://twitter.com/velvetmmith/status/1162839678959177728?ref_src=twsrc%5Etfw

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Brown, who's known for her role as Eleven on Netflix's "Stranger Things," is a fan of Grande and the two appear to be friends. In January 2018, the "Sweetener" singer praised Brown's Golden Globes outfit, calling her "gorgeous" and "stunning" in a screenshot shared on Instagram.

For Brown's birthday in February 2019, Grande also commented on one of the actor's Instagram posts and wrote: "u have such a big heart. anybody who knows u (even just a little) is v lucky indeed. i'll jus be here loudly reminding u of that whenever u need me! hbd ily."

In June 2019, Brown also shared a photo with the singer, saying, "ily sis."

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For his part, Styles actually wrote one of Grande's songs called "Just a Little Bit of Your Heart," which appears on her "My Everything" album. Styles went on to cover the song while on tour in 2017 and at Grande's 2018 benefit concert that honored the people killed during a bombing that took place in Manchester, England, at her concert.