The 40-year-old Wanderlust actor revealed to chat show host Ellen DeGeneres that the Friends star has "been obsessed" with making him bust some moves to entertain her, ever since she saw him dance in Zoolander.

Justin said: "My girlfriend, I don't know if you guys know her, but ever since she saw Zoolander she has been obsessed with making me breakdance.

"There is a rule that I have. I have a very particular pair of shoes, which I breakdance in, I breakdanced at a friend's wedding, so she been saying, 'When are you going to breakdance?'."

"So I invented this thing, I said I have this pair of shoes and if I don't have my 'breaking shoes' then I don't breakdance. We got home that night and it was late and she came out with my breaking shoes and she said, 'Put on the shoes! Breakdance!'."

Ellen then produced his shoes, which she said Jennifer had sent to the show especially, and Justin was forced to breakdance for the audience, to rapturous applause.

The couple star together in new comedy Wanderlust, but Jennifer has recently insisted their relationship did not happen until after they had finished filming.

She told movie blog TheWrap.com: "Nothing happened on that movie, it's the easy rumour. Nothing happened, we were just friends. I have known Justin a long time."

Justin recently said the pair were very happy together.

He told New York Magazine: "I understand the curiosity, but other than saying I am happy, I am not going to indulge it. That's building your own torture device."