Aaaah, that would explain her ensemble at last week's Elle Style Awards...

Taking to her Instagram over the weekend, the 27-year-old model/actress posted a picture containing a spinning top, a toy dinosaur (very Peppa Pig... or Barney. We'll go with Peppa because Barney, despite being over for over a decade, still fills every parent with dread), and - rather more tellingly - a post it with the words "I'M HAVING A BABY" in caps. 
 

If that weren't explicit enough, she also captioned the photo with "I am very happy to tell you ... http://news.impossible.com/woman-has-impossible-baby/"

That link goes through to a post on her site Impossible.com, which bares the following: "The first known impossible baby is being born! I met Kwame when I was in the process of developing Impossible and he offered the most profound gift, to help build the platform. After working together for a long time Kwame and I fell in love, and I am very happy to share our news that we are expecting our first child together..."

The Kwame in question is her business partner, Kwame Ferreira. 

You're all seeing Moss off the IT Crowd, aren't you... Lily is joining an ever expanding list of celebrities due babies in 2015, like Keira Knightly, Zooey Deschanel, Liv Tyler, Charity off Emmerdale, Benedict Cumberbatch's wife Sophie, Abbey Clancy, Olivia Coleman, Helen Flanagan, Frankie Bridge, Kate Middleton....