The pair were rumoured to be dating last month, when Harry was pictured out for dinner with Kimberly, Rod and his wife Penny Lancaster in LA.
Rod Stewart and Harry Styles
Now Rod has confirmed what the pair were up to on Alan Carr's 'Chatty Man', saying: "His [Harry's] car was here in the morning. Let's put it that way. But he may just have come round to pick something up...."
Realising his error, he added: "Bo*****s, I've let the cat out of the bag. Harry couldn’t be a kinder. He is very funny guy."
Kimberly is 14 years older than 19-year-old Harry, and also has a two year old daughter with ex partner Benicio Del Toro.
Let it never be said that Harry doesn't have a type.