While making the most of her time off between Eras Tour dates on Tuesday, June 11, the “Fortnight” hitmaker, 34, headed to Argentinean restaurant Casa Cruz in Notting Hill, London, with several friends including Cara Delevingne, Kate Moss, Haim sisters Este and Danielle, Lena Dunham, and more.

During the fun night out, Swift and her pals started singing Newton-John’s Grease track “Hopelessly Devoted to You,” a source tells PEOPLE.

Taylor Swift is joined by the Haim sisters and Lena Dunham on night out in London’s Notting Hill.
GoffPhotos.com

“They were all singing it on this balcony. It was really loud!” the insider says. “They were in the club from around 8:30 p.m. [local time] to past midnight. So they all had a good time.”

“Taylor was fully making sure all her guests were taken care of and really well looked after,” the source adds.

The PEOPLE Puzzler crossword is here! How quickly can you solve it? Play now!

Taylor Swift enjoys night out in Notting Hill, London.
GoffPhotos.com

The insider says Swift just walked “through the front door like anyone else would.” “She arrived with the Haim sisters and Lena and said, ‘Hello’ to a few people outside but that was about it,” the source tells PEOPLE.

“She was happy. They were all laughing and joking as they walked in. Above the front door of the club, there’s an outdoor balcony area and they all sat outside for the whole evening. You could really hear them. They were so loud chatting away, really laughing and joking,” the source continues.

Phoebe Waller-Bridge has night out in Notting Hill, London.
GoffPhotos.com

Stella McCartney, Phoebe Waller-Bridge, Andrew Scott, The Pretenders’ Chrissie Hynde, and Delevinge’s girlfriend Minke also joined Swift for the star-studded outing.

Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories.

Phoebe Waller-Bridge and Stella McCartney during the outing.
GoffPhotos.com

Mert Alaş, who shot the cover of Swift’s 2017 album Reputation, was also at the dinner and was pictured leaving with Moss in images shared on X (formerly known as Twitter).

Swift was dressed to impress for the outing, wearing a black corset top and matching pants underneath an oversized gray jacket. She completed the look with burgundy heels, a black choker necklace, and her signature red lipstick.

Kate Moss also joined the night out in London with Taylor Swift.
GoffPhotos.com

The musician’s outing came amid news that her ex, The 1975’s Matty Healy, is engaged to model Gabbriette Bechtel.

The pair — who were first linked in September 2023, three months after Healy and Swift split — announced the news after attending mutual friend Charli XCX’s Brat concert in Brooklyn on the same evening Swift was spotted out in London.

Swift is set to continue her fleet of U.K. concerts this week. The pop singer will perform her 100th Eras Tour show in Liverpool on Thursday, June 13. She’ll also take to the stage in the city on June 14 and 15 before heading to stadiums in Cardiff, Wales, and London.

Fans have been speculating Swift could have a big announcement up her sleeve for her 100th show, given that the date includes her lucky number 13.