Madonna giggles every time she thinks of husband Guy Ritchie's love of martial arts - because she's convinced it's little more than heterosexual men making love.

The pop superstar accuses the British movie-maker of "usurping" her security guards and turning them into his "ju-jitsu partners" - and she find it hilarious.

She says, "I think men can't resist the invitation to fight one another and they get into their shorts and they lay down on the floor and they just hug each other for two hours.

"They sweat and they hug and they grunt and they sit on each other's faces.

"My husband's more into it with the people he does ju-jitsu with than he is with me - like, sometimes I walk in and I'm like, 'We haven't done that position!'"