• Billie Eilish and her boyfriend Matthew Tyler Vorce attended Doja Cat's 26th birthday party at L.A. hotspot Delilah Wednesday
  • The couple was "inseparable, sharing kisses," during the bash, a report says
  • Doja Cat's other guests included Malia and Sasha Obama, the Biebers and Bella Hadid

Billie Eilish cozied up to her boyfriend Matthew Tyler Vorce at Doja Cat's birthday bash this week, according to a report.

The "Happier Than Ever" singer, 19, and her 29-year-old beau were among the guests at Doja Cat's undersea-themed 26th birthday party at the Los Angeles hotspot Delilah on Wednesday night, Page Six reported.

Eilish, who wore a lobster costume to the bash, and her self-described "actor, writer, degenerate" boyfriend "were inseparable, sharing kisses," an unnamed eyewitness told the outlet.

"They kept close to each other the whole night and never left each other’s side," the source added.

Eilish started dating Vorce earlier this year, but the pair were not seen together in public until April, when they were photographed on a cozy stroll in Santa Barbara, California.

Aside from Eilish and her boyfriend, other guests at Doja Cat's bash included French Montana, Bella Hadid, Tyga, Winnie Harlow, Karreuche Tran, Malia and Sasha Obama and Teyana Taylor. Justin Bieber and his wife Hailey Baldwin were also in attendance.

"Everyone was going up to her and giving her hugs and saying ‘Happy Birthday,'" the tipster told Page Six of the birthday girl.

Doja Cat wore pale blue bandeau and loincloth-like skirt and sported a white wig as she channeled Princess Kida from "Atlantis: The Lost Empire" during her undersea-themed bash.

"[Doja Cat] was in the best spirits celebrating with her friends and family. The DJ played a couple of her songs, and everyone was dancing and singing along," the source added.

Eilish previously dated rapper Brandon Quention Adams, who performs under the stage name 7:AMP. The ups and downs of their relationship played out in her documentary "Billie Eilish: The World’s a Little Blurry," which was released in February on Apple TV+.

In the doc, the pair hit a breaking point in April 2019, when Q traveled to Indio, California, to support her at her first-ever Coachella performance. Eilish became visibly frustrated when he did not make time to meet up with her afterward.

Eilish later told her parents, Patrick O'Connell and Maggie Baird, that a "self-destructive" Q broke his hand by punching a wall, which worried her father in particular.

Adams faced backlash following the release of the documentary. He later defended himself, saying he was going through a painful experience when he and Eilish were together because his brother had passed away.

"Anyone who knows me knows where my heart is," he wrote on his Instagram Story at the time. "I stay with a smile on my face even when I'm hurting. We push through the pain. [No love is ever lost] but I refuse to be bashed." 

He ended his statement by saying, "There's always two sides to a situation."

The Oscars have a lot to do to compete in the musical stakes with the Grammys, where soon-to-be James Bond songstress Billie Eilish won multiple awards The Oscars have a lot to do to compete in the musical stakes with the Grammys, where soon-to-be James Bond songstress Billie Eilish won multiple awards Photo: AFP / Frederic J. BROWN