Nicole Richie and Joel Madden were only two of the guests at Christina Aguilera’s star-studded 28th birthday. The “Clockwork Orange”-themed event was held at Osteria Mozza and then the SLS Hotel last night and included Paris Hilton and Benji Madden.

I love Christina and Jordan’s costumes! Clockwork Orange is a pretty original party-theme and it looks like a lot of fun.

Christina Aguilera worked the red carpet this weekend at the American Music Awards, but her mind was still on mommyhood. Christina’s son, Max, was born only hours apart from Nicole Richie’s daughter, Harlow, and the two have bonded over becoming new parents.

At the AMAs, Christina was asked what its like to be a working mom and about her support group. She gushed about what a fantastic mom Nicole is and how she often looks to Nicole for motherly advice. Christina talks about Nicole at 0:55 in the video below.

I love the idea of Nicole being strict mom! On one hand, it makes no sense, but on the other hand, I can totally see it! I wonder if Christina, Nicole and Ashlee Simpson will have a mommy-and-me playgroup any time soon!

Nicole Richie and fellow mom Christina Aguilera enjoyed a girls’ night out at Villa in Los Angeles on October 3.

In this video, Christina arrives first and refuses to look at the cameras as she gets out of the car. The paparazzi ask some weird questions, like what she thinks of OJ Simpson being named guilty. Nicole is in the car with her, wearing a cute purple dress, and Joel is there too. The paparazzi seems uninterested in Nicole and Joel, though.

See photos here.

The sales numbers are in and the issue of People featuring Nicole Richie and her and Joel Madden’s daughter Harlow was a huge seller for the magazine.

The issue sold 1.8 million copies, although this is unconfirmed by People themselves. It did better than the issue featuring Christina Aguilera and her son, Max.

Why are people so interested in Nicole?

“There’s also a greater element of curiosity with Nicole,” a source told MSNBC. “She’s gone public about being a heroin addict. Her boyfriend is covered in tattoos. By default, she’s got the more interesting baby. People want to see how she settles down. They want to see what kind of baby someone with her background has.”

OK! Magazine has found out why Nicole Richie has been looking so svelte post-pregnancy–Spanx!

Nicole looked amazing when she was at the various Grammy parties.

“She sometimes wears two pairs at a time,” a source told the magazine.

Joel Madden’s been super helpful with this entire thing too.

“He’ll help her find them in her closet if they’re running late,” says the friend. “But he thinks she looks great just the way she is.”I know OK is gossipy mag, but this tidbit isn’t out of the realm of possibility.

If it’s true, I bet Nicole will even joke about it in an upcoming interview–Harlow’s baby pictures should be on stands soon!

I love these pictures of new mamas Nicole Richie and Christina Aquilera chatting together at Clive Davis’s Pre-Grammy party. They both look gorgeous and it certainly quells those silly feud rumors!

Click images to enlarge. Images courtesy Xtina Web via The Fashion Spot.

According to Pop Crunch, Nicole Richie was a dream patient at Cedar-Sinai hospital while daughter Harlow was being born.

“Nicole was a big hit with the nurses and the other women giving birth,” their source says. “She bought six other mothers having babies the same day ‘push gifts,’ including gift certificates to Target, teddy bears, balloons and a card wishing them luck. She also had all of the nurses in stitches with her wry humor.”

They said Nicole was “humble” and “witty”, unlike another celebrity patient that weekend–Christina Aguilera.

X-tina was supposedly a tyrant and “the nurses were happy to see her go!”

In baby photo news, Gawker has news “from someone who particpated in the auction” that the magazine who scored the first pictures of Harlow Madden is indeed People!

Thanks to Jasmine for the tip!