Reality TV stars Ozzy and Sharon Osbourne have vowed never to have more children because they're too old.

The rocker considered expanding his brood with wife Sharon, but realised he'd be crazy to put himself through the rigours of fatherhood again.

He says, "I went through that phase for about five minute once. Then I thought, 'What are you f**king thinking?'

"It's like putting a gun to your head, shooting, missing and then thinking, 'I've missed. I'll try again.'

"Some people over the age of 60 can do it. But at the age of 57, I want to change somebody's diaper like I need a hole in the head."