Nicole Richie takes ''responsibility'' for Benji Madden and Cameron Diaz getting together.

The 32-year-old socialite - who is married to the Good Charlotte rocker's twin brother Joel Madden - ''approves'' of the couple's new relationship and admitted she was the one who got them together.

Asked on 'Watch What Happens Live' if she set them up, she said: ''Yes. I'm going to take responsibility for everything!''

Nicole - who has children Harlow, six, and Sparrow, four, with Joel - is delighted her brother-in-law has found happiness with the 'Sex Tape' actress in recent months.

She added: ''I approve of anything that's going to make Benj happy.

''I am a devoted sister in law. I'm happy for anyone who is happy, and I want everyone to be surrounded with love.''

It was previously claimed that 35-year-old Benji is ''madly in love'' with the 41-year-old actress, but she doesn't want to rush into anything serious.

A source said recently: ''Benji is madly in love with Cameron, but she wants to take it slow -- he isn't her usual type. He has dated a lot of Nicole's friends in the past but Nicole really wants this one to work.''