SSSSHHHHH. Just don't tell anyone. It's meant to beee a seeeecreeeeeeet.

Her vegan baker boyfriend Matthew Mosshart popped the question a few weeks before Christmas and now the couple - who have been dating for around 18 months, a lifetime in celeb years - are "really excited" about planning their nuptials.

A friend added to Us Weekly, possibly while twirling in a meadow filled with butterflies and floating petals: "Kelly is the happiest she's ever been. Her career is going well, and she's in a healthy relationship with a wonderful guy.'

The wedding is set to take place in Kelly's native UK this summer. Because this corner of the planet gets super weather in the summer... Get married in LA, Kelly, get married in LA. 

Here's a bit of background info. Kelly and Matthew met at the nuptials of Kate Moss and Jamie Hince in July 2011 but didn't go public with their romance until five months later. Of their love, she recently 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."

Ozzy and Sharon are smitten too: "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."