Dakota Johnson joins Lily Allen on Saturday Night Live in surprise cameo

Dakota Johnson surprised fans by joining Lily Allen on Saturday Night Live (SNL), marking the singer’s first appearance as the show’s musical guest in 18 years.

Allen performed songs from her recent album, West End Girl, reportedly inspired by the alleged infidelity of her ex-husband, actor and Stranger Things star David Harbour.

Johnson’s surprise cameo came during Allen’s second song of the night, Madeleine, in which she portrayed the titular enigmatic mistress, concealed behind a curtain for most of the act.

The American actress also delivered the song’s spoken-word outro, explaining her side of the story via texts to Allen.

“He told me that you were aware this was going on and that he had your full consent,” she said.

“If he’s lying about that, then please let me know. Because I have my own feelings about dishonesty.”

At the end of the song, Johnson revealed herself by stepping from behind the curtain, approaching Allen, and planting a kiss on her cheek.

The episode was hosted by English actor Josh O’Connor.

Earlier, Allen performed her first song of he night, Sleepwalking, dressed in silk nightwear against a bedroom-styled stage backdrop.

The record, described by Allen as a blend of “truth” and “fantasy”, saw the pop star explore a broken sexual “arrangement”.

Allen last appeared on the long-running sketch comedy show in 2007, on an episode hosted by actress Drew Barrymore.

All 14 songs on her new album were written by Allen, in collaboration with her musical director Blue May.

The SNL performance caps off a huge year for Allen, who just last month announced a string of new live dates to her sold-out tour.

Allen, who will perform her new album West End Girl in its entirety, will now also appear in Leeds, Glasgow, Manchester and Cardiff, along with several other towns and cities in June.

The original tour dates were announced last month, with all 13 shows quickly selling out.

The shows will mark Allen’s biggest headline tour of her career. Her previously announced performances will take place in March, while the new shows will begin in Newcastle on June 16, with the ninth and final date in Dublin on June 30.

Allen will also perform West End Girl at Mighty Hoopla in London’s Brockwell Park in May.