Sam Smith wants a funeral for his "single self" to take place immediately before he gets married.

The Stay with Me singer, who is reportedly dating 13 Reasons Why actor Brandon Flynn, revealed to James Corden during a new episode of Carpool Karaoke on Wednesday night (01Nov17) that he had already thought out his wedding day, and some bizarre plans for it.

"I want a funeral for my single self before my wedding," he said. "So, everyone comes to the church, I'm in a coffin and then there's all these PowerPoint presentations about my single life, like how fun it was, and everyone's crying like, 'Oh no.' And then I raise from the coffin, everyone takes off their black clothes and they're wearing white and the wedding begins. Fifth Harmony would come out."

The 25-year-old Brit is a self-confessed "Harmonizer", the term given to Fifth Harmony fans, and is so "obsessed" with their 2016 hit Work from Home that he wants it to be played at his wedding.

"When I hear them, I feel free, I feel alive, I feel like the woman in me is on fire!" he said. "Work from Home, I listen to every time before I go out. I think it's my wedding song. I want to walk down the aisle to it in heels. I would love it if I got Fifth Harmony out at my wedding."

James then surprised Sam by pulling the car over and calling an unknown person to help with their rendition of Work from Home, and Sam couldn't hide his shock when Ally Brooke Hernandez, Normani Kordei, Dinah Jane Hansen and Lauren Jauregui jumped onto the backseat of the car.

"Oh, I'm dead! No! Oh my God!" he yelled, before screaming and giving them all hugs. "I'm shaking. I'm actually shaking. Oh my God, this is my dream!"

After they sing the song together, he shared, "That was my dream come true!"