The model watched the McBusted drummer - who is happily married to wife Izzy Judd - in action as he performed as part of the boy band at Hyde Park earlier this year, and the pair had an enjoyable conversation about playing with their sticks afterwards.
He said: ''I saw her afterwards, I met her through Ellie [Goulding]. She seems really nice. We bonded over drumming.''
As well as meeting Cara at the gig, Harry admitted headlining the show at the iconic London venue over the Backstreet Boys was the most ''surreal'' moment of his career so far.
He added: ''It was probably the most surreal thing so far.''
But one thing that is not surreal is Harry's bandmate Dougie Poynter's relationship with Ellie Goulding and the stickman admits the couple are ''very happy together'' and isn't surprised they took their time to confirm their romance.
He added to OK! magazine: ''It's each to their own. I think in the early stages, you don't want to introduce people.
''You want it to play out normally. I think when they really liked each other and were boyfriend and girlfriend, when they happy and comfortable, then it was OK to tell everyone.
''They're great, they're very happy together.''
There's already an Oscars buzz surrounding this movie.