"All the scenes were carefully planned. It's going to be a very sexy video. Zayn was dressed dapper and Taylor was wearing garters and heels."
Taylor flew into London from Nashville in the US via a private jet to shoot the video, but quickly returned home after filming was concluded.
The source told The Sun newspaper: "She flew straight back to Nashville and left him alone."
Last month, meanwhile, Zayn revealed his girlfriend Gigi Hadid helped set up his collaboration with Taylor.
The 23-year-old star asked Taylor to sing on the track - but he wasn't nervous about her agreeing to be part of the song because he knew she already liked it thanks to model Gigi.
He shared: "The interesting thing was, she is friends with Gi, so she already reached out after hearing it because [producer] Jack [Antonoff] had just played her the song anyway and she went in the studio the next day to record it.
"She mentioned to me that she liked the song so I already kind of knew in the back of my head that she liked it, so I asked her if she wanted to be on it and she was cool with it."
-Bang! Showbiz