I stand corrected - It should be: "IF MY LOVIN' WORKS FOR YOU THEN"
DISCLAIMER: NO COPYRIGHT INFRINGEMENT INTENDED. The song was co-written by Harry Styles and Meghan Trainor. Meghan said in an interview that "It's about how, you know when you date someone, and then you break up, and then you see them on a date with someone else but they're so happy, so you're like, 'I'm happy for you. Maybe some day in the future if we're back together, that'd be cool. Good luck. I haven't seen that smile in a long time, that's great. Maybe some day when we're old and gray, we could be in love once more.' Oops, there's a line!"