Nicole Richie is ''so excited'' that Benji Madden is dating Cameron Diaz.

The reality TV star, who is married to Benji's twin brother, Joel Madden, recently played match-maker and set 'The Other Woman' star up on a date with her brother-in-law, and is thrilled they've hit it off.

A source told America's Star magazine: ''Nicole initiated the whole thing by inviting both of them over to her house. She knew they would get along.

''She's so excited that things are working out between them. And it's and added bonus that she doesn't have to deal with getting to know another one of Benji's new girlfriends.''

Cameron and Benji's romance is starting to heat up and they have been spending lots of time together.

The insider said: ''She loves that he's a bad boy with a heart of gold. He's really making her happy. Cameron wants to spend as much time with him as possible.''

Cameron has previously admitted to having a romantic liaison with another woman.

She said: ''I have been with a lady, yeah.''