Jennifer Lopez has taken to her Web site to deny rumors she's engaged to marry boyfriend Casper Smart. The rumors began in March when a fake Tweet from fashion designer Roberto Cavalli implied he was making a wedding dress for the actress, People magazine reported Saturday. "Rumors!!! Don't be fooled by the rocks that I got," Lopez wrote on her Web site. "No engagement!" Since the March Tweet by Cavalli, Lopez has been photographed with what appears to be an engagement ring on her finger. "What's the best way to stop a false rumor?" she posted Friday, along with a self-portrait showing no engagement ring on her ring finger.