(Cover) - EN Showbiz - Christina Aguilera will reportedly sing at Nicole Richies wedding.

The 29-year-old star is engaged to rocker Joel Madden, and recently confirmed their wedding will take place soon. It has now been claimed Nicole is planning a winter wedding and will tie the knot over the first weekend of December. Nicole has asked her close friend Christina to perform during the ceremony and the singer was thrilled to accept.

The pair partied at Soho House in Hollywood over the weekend with Joel and Matthew Rutler, a set assistant from Christinas new movie Burlesque. Throughout the evening, Nicole and Christina were overheard excitedly discussing wedding plans.

"Nicole and Christina were chatting non-stop about Nicole's upcoming nuptials, a source told X17online. And I even overheard Nicole talking to Christina about possibly singing a song at Nicole's wedding!"

Nicole and Joel have been together since 2006 and have two children, daughter Harlow, two, and 13-month-old son Sparrow.

Meanwhile, Christina is believed to have been on a string of dates with Matthew since she announced her split from her husband Jordan Bratman.

The pair became good friends when they met on the set of Burlesque and Matthew has been offering Christina support since the breakdown of her marriage.

Although the pair have formed a close bond, the 29-year-old star doesnt want to rush into anything serious.

"He's been really good for her and is helping her through this difficult time," a source told UsMagazine.com. "They've been on a few dates over the last few weeks. It's not serious. She's not looking to jump into a relationship right now. She has a lot going on with the movie and is focusing on spending as much time as possible with her son Max." (C) Cover Media