Big Time Rush singer Carlos PenaVega opened up about touring with an early One Direction on the Unplanned podcast.

The two boy bands shared the stage in 2012 for BTR's Better With U tour.

At the time, 1D was fresh off of The X Factor and had released "What Makes You Beautiful" and "Gotta Be You" as singles in the U.K. in 2011.

During their run as openers for BTR, the frenzy over 1D had already begun, and "What Makes You Beautiful" officially dropped as a single in the U.S., debuting at No. 28 on the Billboard Hot 100.

"After our show, fans were outside the theater chanting for One Direction. That was really hard for us," PenaVega revealed.

READ MORE: Big Time Rush Talks Reunion, New Album

"Our tour was sold out before they got on. So, they were there to see us. But it was like The Beatles. It was like a freak of nature. They wanted these five, cute British boys," he continued.

Later, the One Direction boys offered to return the favor in the U.K.

"They offered for us to open for them in the U.K. and our egos got in the way. We were like, 'No. Never.' Probably should have done it. I mean we were kids. I was like 22. It's hard to control your ego at that age," he explained.

"Respectfully, thank you for saying no bc 5SOS opening for them will always be the most iconic tour of 1D," one fan joked in the comments of a TikTok video from the podcast.

"I remember this so well Big Time Rush fans were SOOOO MADDDD half the crowd was always gone after 1D JDJDJDJD," another viewer commented.

Another person echoed the same thing, noting that fans leaving after One Direction's performance sparked a "war of the fan bases" between 1D stans and BTR fans.

"One Direction opening for them was like a fever dream. 2012 was wild," someone else said.

Artists Who Canceled Their Concert Tours

Even stars like Adele, Justin Bieber, Kanye West and Britney Spears have had to cancel tour dates. Below, check out 25 artists who canceled their concert tours due to injuries, illness, tragic circumstances and other surprising reasons.

Gallery Credit: Erica Russell

More From PopCrush