Cameron Diaz is desperate for a baby.

The 'Sex Tape' actress wed her husband Benji Madden in a secret ceremony at their Beverly Hills home in California on Monday (05.01.15), and it has now been revealed the couple decided to marry because the 35-year-old musician is ''old-fashioned'' and wanted to be legally together before they started their family.

An insider told E!: ''She told Benji she really wants a baby. And he said, 'Well, marry me.' He's old-fashioned ... Marriage was important to him.''

The Good Charlotte guitarist and vocalist also recently explained he is keen to have kids, admitting children are ''what every man wants, whether they admit it or not.''

Meanwhile, Cameron, 42, spoke of her desire to become a mother last year, saying she cannot imagine herself being ''childless'' and would be open to the idea of adoption.

She said: ''If I wanted kids, at any point in life, I would have them. But I'm certain that if at any point I wanted a child, that child would find its way into my life, whether through adoption, or through being in a relationship with somebody who has a child.

''I can't see the future, but one thing I do know is that I'm not childless. I have a ton of children in my life. I can have a kid any second, if I want. All my friends would be like, 'Sure, come and get them.' ''

Despite both of their wishes to bring up children, an incident involving their ring bearer, Sparrow Madden - the son of Benji's brother Joel, and wife Nicole Richie - almost ruined their wedding ceremony, at which there were performances from Lionel Richie and Ryan Adams.

A source told MailOnline: ''He dropped the ring and it rolled around. The audience began to chuckle.

''But as both brothers - groom Benji and best man Joel - got on their hands and knees looking for it, the guests broke out into full laughter.''