Nicole Richie has ignited reports she is to wed boyfriend Joel Madden after she was spotted at a Hollywood party wearing a large diamond sparkler on her ring finger.

The Simple Life star has so far refused to confirm or deny recent reports of a rumored pregnancy, prompted by pictures of the skinny star with a bloated belly.

And now the Good Charlotte rocker–who accompanied Richie to the YSL Pool Party at the Beverly Hills Hotel on Thursday night–appears to have proposed to his lover.

An eyewitness tells the New York Post’s gossip column Page Six, “It was one big rock surrounded by more diamonds.

“(Madden was) overly attentive to her–keeping his arm around her all night–and repeatedly asked her if she was OK.” (WENN)

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Paris Hilton Beverly Hills