He may have a tough guy image – but hunky Hugh Jackman admits that he can have moments that leave him mortified.

Speaking about his upcoming movie, Butter, he told The Huffington Post about one filming moment with co-star Jennifer Garner that made the Australian actor blush.

"I did probably one of the most embarrassing things I had to do on a movie set, or funny anyway," he recalled. "We have an off-screen love scene, Jen and I, and it takes place in the back of a car, you don't see anything. We had to record it in a car.

“The director, in the driver's seat, and the passenger's seat had the sound recorders. It was stationary because it was in the showroom. And we were doing it at the same time, which is one thing, but then the guy said, no, this is not going to work."

The actors were then instructed to make their contributions separately, a situation that left Jackman not knowing where to look. "And so, we both had to kind of perform our version, in character, of sex while the other one is quiet.

“And it was impossible not to be laughing your head off while the other person is doing it. That was humiliating,” he admits. “Guys never sound good during sex. It's impossible to sound good."