A source said: ?Harry made a beeline for Cara as soon as he spotted her. Everywhere you looked there were models, actors and aristocrats but Harry and Cara didn't seem to notice. They spent the whole afternoon only talking to each other.?
"The theme for the party was Hollywood Westerns. Cara kept stealing Harry's cowboy hat and teasing him about his boots. He seemed to love it and obviously thought she was hilarious,? the source added.
Harry has reportedly seen Delevingne, 20, several more times and presented her with a cheeky gift during their last meeting.
The source said: "It was a silly thing - an in-flight magazine, which is a running joke between them to prove who has the most jet set lifestyle."