Billie Eilish takes fans inside her home during Carpool Karaoke

Billie Eilish, on her 18th birthday, took her fans inside her house where she recorded her world-famous album Don't Smile at Me during Carpool Karaoke.

Billie joined James Corden for his Late Late Show segment on Thursday. The duo kicked off the show singing along and jamming in SUV. Later, the songwriter also opened up about freaking out when she spotted Justin Bieber in Ariana Grande’s concert.

The Don’t smile at Me hit maker also sang the song, Ocean Eyes, which she wrote at the age of 13. Getting emotional, Billie shared, "I haven't listened to that in so long. That song is the reason that I have the life I have."

The 18-year-old then opened up to Corden about her brother Finneas, who is also the co-creator of her album, and how he supported and helped her to make the things work out.

Eilish also took Corden to give a brief house tour to her home, and showed him her brother’s room, where the entire album was recorded.

"Before we made any songs together, Finneas said [something], kind of as a joke, but we were talking about making music together, and he goes, 'I'm gonna make you the biggest pop star in the world.' And we just laughed," Eilish reflected.

Billie’s mother, Maggie Baird, also spoke about watching her daughter perform, "People are like, 'How does it feel that she's singing at Radio City?' Like, it blew my mind when she sang at the Hi Hat. It blew my mind when I sat here and heard Billie and Finneas play a song. It's never not been mind-blowing," Baird shared. "So it's almost been like four years of, 'Oh my God," she said.