Kelly Osbourne is secretly engaged to Matthew Mosshart. OMG!

Kelly Osbourne has seemed ridiculously loved-up with her boyfriend Matthew Mosshart for a while now - and now we know the reason for her big happy grin.

Kelly Osbourne and Matthew MosshartKelly Osbourne and Matthew Mosshart are apparently secretly engaged. Copyright [Rex]Apparently Kelly Osbourne and Matthew Mosshart are engaged - and have been since before Christmas.

[Related article: Lady Gaga responds to claims that she's bullying Kelly Osbourne]

[Related article: Kelly Osbourne suggests Lady Gaga is pregnant]

Apparently Matthew proposed to Kelly a few weeks before Christmas and the pair are already planning their big day.

A source said: "Kelly is the happiest she's ever been. Her career is going well, and she's in a healthy relationship with a wonderful guy."

Kelly and Matthew have been together for 18 months. Copyright [Rex]Kelly and Matthew have been together for 18 months now and Kelly recently gave a VERY gushing interview about how much she loves him.

The star said: "I couldn't believe that he truly liked me because I never think people ever could. But I'm so happy. I don't think I've ever really known what love is like before."

Wowzers.

Apparently Kelly's parents Sharon and Ozzy 'love' Matthew. Copyright [Rex]Apparently Matthew is also a massive hit with Kelly Osbourne's parents, Ozzy and Sharon.

The source went on to add: "Kelly's family love her boyfriend. They think he's the nicest guy she's ever dated. He is very patient and down to earth."

Well we reckon Kelly should get planning the wedding pronto. She has a whole host of celebrity mates so it should be a star-studded occasion.