It looks there may be a new son-in-law in the First Family of Darkness. According to Us Weekly, Kelly Osbourne -- reality TV star and daughter of rock icon Ozzy Osbourne -- is secretly engaged to her boyfriend, chef Matthew Mosshart.

A source close to the couple tells the magazine they quietly got engaged just before Christmas. Osbourne, 28, is the co-host of the E! reality show 'Fashion Police,' and she met the 29-year-old chef a year and a half ago at the wedding of her friend, model Kate Moss.

While the pair have remained publicly mum about their engagement, Osbourne has not been shy about her feelings for Mosshart. "I'm in love and I don't care who knows about it!" she tweeted last June.

"Kelly is the happiest she's ever been," a friend of hers tells Us. "Her career is going well, and she's in a healthy relationship with a wonderful guy."

Maybe this means Ozzy will become a grandfather yet again. Kelly's brother Jack got married just last October, and his new daughter Pearl spent New Year's Day with her doting grandpa, otherwise known as the Prince of Darkness.