Nicole Richie is the perfect sister-in-law.

The 32 year-old star apparently set up her good friend Cameron Diaz with Benji Madden, her husband's twin brother and Good Charlotte band member.

This revelation came when Richie appeared on Bravo TV's 'Watch What Happens' Live!' this past Tuesday (July 8th).

"I'm going to take responsibility for everything!" she told the host Andy Cohen about showbiz's newest romance.

Adding, "I approve of anything that's going to make Benj happy."

The former 'The Simple Life' star was previously reported to have introduced Cameron to Benji when their relationship first became public knowledge back in May.

Richie, who has been married to Joel since December 2010, also said, "I am a devoted sister-in-law and I am happy for anybody who's happy, I want everyone to be surrounded with love."

The pair are also parents to two children, daughter Harlow Winter Kate Madden (born 2008) and son Sparrow James Midnight Madden (born 2009).

So far it seems Richie's matchmaking skills are a success as Diaz reportedly introduced the musician to her family when celebrating America's Independence Day holiday weekend. The smitten duo travelled from Los Angeles to Florida to attend the 41 year-old's family reunion in Tampa.

"They flew into Orlando and then drove to Tampa where they met up for a reunion," an insider revealed. "They also spent a few days at the beach on Anna Maria Island, where Cameron's family has a house."

Benji Madden
Benji's twin brother is married to Nicole Richie 

More: Cameron Diaz 'Really Happy' With Benji Madden

"It was a great vacation and they had a blast spending time with Cameron's nieces and nephews. Cameron and Benji are like big kids themselves. They were having a great time jumping over waves and splashing in the water. They were giving the kids piggyback rides and seemed like the best babysitters ever," the source continued.

More: Cameron Diaz Talks Appearing Nude On-Screen For First Time Ever In 'Sex Tape'

Adding, "The kids all couldn't wait to hang out with Cameron and Benji was right there with her having fun."

Diaz reportedly introduced Madden to her family over the weekend