Hailey Bieber defended as fans spot detail during Justin Bieber’s Billie Eilish ‘One Less Lonely Girl’ moment

Over the weekend, Billie Eilish got to do what many teen girls in the 2010s dreamed of - be Justin Bieber's 'One Less Lonely Girl'.

Now, hardcore fans of the Canadian singer, 32, will know that when he performed the song in his younger years, he would invite one girl on stage to be his 'lonely girl' during the performance, sing to her, and give her flowers.

And he decided to bring the sweet concept back for his second Coachella headline performance on Saturday (18 April), bringing none other than Billie Eilish up onto the stage.

The 24-year-old singer, who has famously been a huge Belieber since she was a teenager, joined the 'YUKON' hitmaker on the stage during the throwback segment of his performance.

In the now viral moment, Billie can be seen dancing in the crowd in front of the festival's VIP box with Justin's wife Hailey Bieber, 29, who appeared to encourage her to go on the stage.

Seemingly unable to believe what was happening, Billie laughed and covered her face in shock as she made her way over to the singer, hilariously dropping to the ground in disbelief a few times on the way up.

She sat on a stool on stage as Bieber sang the 2009 anthem to her and hugged her from behind, dropping to the ground again when the song ended.

The adorable moment has quickly made its way around the internet, with fans wanting to know every little detail of how it came about.

At first, some fans were confused as to why Billie was the 'One Less Lonely Girl,' instead of Hailey, who was also in the crowd.

One X user penned: "The fact that he brought out Billie Eilish for one less lonely girl and not his wife."

However, more videos from the night appeared to show Hailey encouraging the 24-year-old to go up and even excitedly giving her a little push through the barrier.

Fans have been praising the Rhode founder for giving Billie her moment, with one writing on social media: "Hailey is a real one for pushing her to the stage."

A second gushed: "Ohh, Hailey, the woman that you are. She really saw Billie’s moment and pushed her to meet Justin Bieber on stage. That was so special. She made her dream come true."

While a third and fourth joked: "Hailey, mother of the Beliebers for real" and "Hailey celebrating, DUDE! What an incredible woman."

And a fifth wrote: "They made her childhood dream come true. Billie will never forget this."

As for how the heartwarming moment came about, some fans have theorised that Justin and Hailey could have pre-planned it as a surprise for Billie, while others are claiming that even Justin didn't know she was coming up on stage.

Tyla has contacted representatives for the Biebers for comment.