The One Direction heart throb joined the 68-year-old rocker, his daughter Kimberley and his wife Penny Lancaster for a meal in Los Angeles.
The 19-year-old pop star - who has history with older women - was spotted kissing and holding hands with the 33-year-old beauty with a source revealing the legendary musician "didn't seem to mind."
The insider told the Daily Mirror newspaper: "They weren't exactly hiding it - Rod was well aware what was going on and didn't seem to mind.
"Harry's well-known for his thing for older women, and Kimberley is a striking blonde so it's easy to see the appeal."
And the 'Little Things' hitmaker looks to have done well without his band-mate and self-professed "wingman" Louis Tomlinson, who recently claimed he helps the well-known romantic flirt with girls.
He said: "I am Harry's wingman. I do help the other boys talk to girls they like. There is a lot of that.
"I'm the really blunt one, so if Harry wanted someone's phone number I'd be like, 'Basically, Harry wants your phone number'."