with the brother of Kills` frontwoman in England last summer, Contactmusic reported.
"Kelly is dating Matthew Mosshart. They met at Kate Moss` wedding and are very much in love. Kelly has learned from her previous relationships and wanted to keep this one quiet for as long as possible. She`s never been happier!," a source said.
Osbourne, 27, has even introduced her new man to her parents Sharon and Ozzy and her friends are said to be keen on him too.
"Matthew is the first guy Kelly has ever brought home that every single one of her friends and family like. And he`s also the first boyfriend with whom she`s had a close relationship with his family," the source added.