Harry Styles surprises James Corden with an unexpected Christmas gift on Carpool Karaoke

The Christmas edition of Carpool Karaoke was a star-studded affair, with guests from the year that is coming to a close making an appearance on the popular late night TV show.

Miley Cyrus, The Foo Fighters, Bruno Mars, Katy Perry, Pink, Ed Sheeran, Sam Smith, Fifth Harmony, Kelly Clarkson, Usher, Harry Styles among others joined host James Corden to usher in the holidays by singing the rendition of Santa Claus Is Comin' to Town while riding around town.

The former One Direction star stole the show as he kissed Corden on the lips after singing the popular song.

Corden turned to the 23-year-old pop star and said, "Happy Christmas Harold." They looked at each other for a while before Styles planted a kiss on Corden.

"Wow, I did not expect that for Christmas!" Corden joked after the lip-lock ended.

This is the third time Styles has appeared on the show. He first appeared on the show in 2015 with his former bandmates Niall Horan, Louis Tomlinson and Liam Payne after the departure of Zayn Malik from the group as he wanted to pursue a solo music career. In early 2017, he once again appeared on the show, as a guest host, and also performed some of his songs from his self-titled solo album.

Meanwhile, Corden has announced that he has become a father once again. Corden and his wife, Julia, welcomed baby number three on Tuesday.

"Today we welcomed a beautiful baby daughter into the world," Corden tweeted. "Both she and her mother are doing great. We can't stop smiling. Thank you Harry for stepping in to host the show at 2 and a half hours notice! x x x."

The couple - who married in 2012 - are also parents to six-year-old son Max, and three-year-old daughter Carey.