The actress appears in the singer’s new video for single Naked after he booked her for her “supreme acting ability”.
In the video, James plays a talk show host who ends up falling for the girl he’s interviewing – Cressida.
James, 29, said: “There was chemistry there. I have genuine aspirations of being an actor.
“In order to convey that on screen, you’ve got to have those thoughts and embody that feeling.”
He added to The Sun: “I was trying to have a spark with her and we had a spark. It was good. She was really professional, really talented. I believe she’s got a boyfriend.”
Despite that, James admitted the pair enjoyed some flirty banter on set, with the star teasing the 28-year-old actress about her posh accent.
James booked Prince Harry’s ex for the video for new single Naked the same week Harry and Meghan Markle announced their engagement, though he insists he had no idea about her royal connections.
James, who is in an on off relationship with dancer Jessica Grist, also spoke candidly about his past sex addiction.
He said his need for validation from women partly stems from his parents putting him in foster care when he was younger.
“I love the affection. It’s not there as much as it used to be, I’m growing up now, I’m getting on and I see now it’s all about self-love and you’re not going to gain much from constantly looking outside yourself for validation,” he added to the publication.