He has no problem with calling Liz Hurley hot on a radio show hosted by a man with "history", but admits his mincing act on a fashion runway was not befitting a prime minister.
John Key yesterday defended his regular weekly interview with presenter Tony Veitch, who was convicted of injuring his partner.
However, he says his modelling performance last week was "a bit stupid".
"In that particular instance, that was a crowd that was boisterous ... I responded to them," Mr Key said yesterday. "I think it was a bit silly. You learn your lessons."
He said his model walk, however, was a different matter from the "hot" comment.
Mr Key continues to ride the wave of popularity, and part of his appeal is considered to be his informal, regular-guy approach.
Responding to questions on Veitch's radio show, Mr Key said he thought Ms Hurley was "hot", actress Jessica Alba "looked pretty hot", and that actress Angelina Jolie was "not too bad".
Green Party MP Sue Kedgley called the comments boorish and unbecoming, and his comments were picked up by British media outlets. But Mr Key did not resile from them, nor from his appearance on Veitch's show.
Veitch was convicted of recklessly injuring his partner after a high-profile case that cost him jobs in media.
Other assault charges were dropped and Veitch was hired by Radio Sport.
"[Veitch] is a guy that's clearly made mistakes, and in the end, hopefully he's learned his lessons," Mr Key said.
"I engage with a lot of journalists. Some of them have history and some of them don't. That's not my concern. My concern is to make sure that I represent the views I want to represent on those shows."
Right-wing political commentator Matthew Hooton said Mr Key's comments were "right on the line", but he did not think it would hurt the Prime Minister's popularity.
It was arguable that Mr Key should draw the line and drop his appearance on Veitch's show, he said.
"[But] if you are on Tony Veitch's show, or anyone's show ... and you're asked, 'is Liz Hurley hot?', the answer to the question is yes, isn't it?
"It would be quite stupid to say no. She is hot.
"If you're going to do shows like that, you're going to be asked questions like that."
Mr Hooton said some negative feedback might encourage Mr Key to be conservative in terms of the events and interviews he gives.
"And that would be a mistake, given that it's served him pretty well and he is the most popular National Prime Minister in history."