Billie Rapped Luda's Verse From Justin's "Baby" On 'Carpool Karaoke' & It Was LIT

Billie Eilish may be one of the most famous teenagers in the world right now, but that doesn't stop her from fangirling over her favorite celebrities just like the rest of us. On Dec. 19, she appeared on The Late Late Show With James Corden for a round of "Carpool Karaoke" and, as a true Belieber, she obvs had to take the opportunity to sing a bit of Justin Bieber. Billie Eilish rapping Ludacris' verse from Justin Bieber's "Baby" will make you want another collab from her and the Biebs desperately.

After belting out "Bad Guy" in Corden's passenger seat, he asked Eilish about which celebrities she's been starstruck by recently. Being the No. 1 Bieber fan she is, Eilish recalled the time she met Bieber during Ariana Grande's Coachella set on April 14.

"Well, if I could be honest with you, all Coachella weekend, I was like, ‘Don’t surprise me with Justin Bieber,'" she told Corden. "I can’t take it. I can’t have to do this show and Justin Bieber’s going to be there."

Eilish then revealed that while jamming out to Grande's set, she noticed Bieber in the audience. "I know his body language, I know how he stands, I know where he wears his pants," Eilish hilariously explained.

Bieber soon noticed her too, and Eilish said they just stood there looking at each other and appreciating the moment before they hugged. "He just stood five feet away from me perfectly still," Eilish said.

Watch the clip of Eilish meeting Bieber below.

The little anecdote led Corden to sing the opening line of Ludacris' verse from one of Bieber's biggest early hits, "Baby."

"When I was thirteen, I had my first love... ," Corden sang, and Eilish finished it off with, "There was nobody that compared to my baby and nobody came between us, nor could ever come above."

Without any music to follow along to, Eilish remembered Ludacris' entire verse from "Baby" off the top of her head, which further proved how big of a Belieber she really is.

Watch Eilish sing Bieber's "Baby" below.

Bieber already hopped on a "Bad Guy" remix, so it would be cool if Eilish returned the favor and hopped on a "Baby" remix. It's been a decade since the song's release in 2009, so there couldn't be a more perfect way to celebrate than with an updated version featuring Eilish.