Zeta-Jones gave kids ultimatum to Douglas

Catherine Zeta-Jones would have refused husband Michael Douglas' marriage proposal if the movie star opted not to have kids with her.

The Chicago star admits Douglas' cheesy chat-up line, "I want to father your children," struck a nerve with her - as she was beginning to think seriously about starting a family.

Zeta-Jones tells America's Parade magazine she then set about discovering whether or not Douglas was serious about becoming a dad.

She explains: "I was already in love with him, but there was one thing I had to be sure of. I turned to him and said: 'Do you really want children?'

"I thought, for that one minute, he was going to say: 'I already have a son, Cameron,' and I would have to say goodbye. I remember saying defiantly: 'I cannot live without having children.' And he went: 'Me too.'"

The couple now have two young kids, Dylan and Carys.