Yesterday, Ashlee Simpson grabbed lunch in West Hollywood with Evan Ross, Diana Ross's 24-year-old son, stirring up speculation that the two are dating. However, Us Weekly reports that Ashlee and Evan are just pals, with a source telling the magazine, "Evan and Ashlee have been friends for a really long time, probably ten years. They know each other from the club scene and have tons of mutual friends." This isn't the first time that Evan has been linked to his famous female friends. Back in January, there were reports that he was dating Rita Ora, a claim that he denied on Twitter, saying, "These blogs aren't true. Me and Rita Ora aren't dating and we weren't making out. We are just friends." Neither Ashlee nor Evan has publicly commented on their dating rumors, but Ashlee may be a bit busy these days as her sister, Jessica Simpson, welcomed her son, Ace, on Sunday.