According to reports, Harry has been slipping in the Daisy DMs in an effort to engage in conversation and, it seems, to see if a flicker of the ex-flame is still there.
However, while Harry has been single since splitting from French model Camille Rowe two years ago, Daisy has recently become involved in a love affair with the music producer, Christian Langdon.
A source from the music industry, told The Sun on Sunday, Harry has carried a torch for Daisy since they were separated, and notes that they are part of the same friendship together.
While the One Direction star is said to be enchanted by the dark-haired beauty – who is the daughter of Bush singer Gavin Rosedale and fashion designer Pearl Lowe.
The source claimed: “Not only does he think she is really cool, with his rock and roll background, but he really loves it too, and like his style.
“He slid into her DMs quite a bit, and is open to enjoy her sexy Instagram photos.”
However, the source suggests that Daisy had to leave the chart topping star gently.
They state: “Unfortunately, she was five years older than him, and while he can handle himself with the older women, she has always seen it as more of a little brother than a lover.”
Harry has been linked to a string of high-profile women since finding fame aged 16 on The X Factor 10 years ago.
He counts fellow musician Taylor Swift, 30, and Keeping Up With The Kardashians star Kendall Jenner, 24, among his ex-girlfriends.