Heidi Klum puts a smile on the face of her followers by posting a topless snap – complete with happy face on her tum.

The supermodel – who turned 40 last month – made the grinning character out of sand and seashells as she sunbathed in black and white patterned bikini bottoms.

And she covered her bare boobs with her hands in the headless selfie.

The Project Runway star flaunted her amazing figure and taut tummy in the Twitter snap.

She captioned the picture with a simple: “Smile!”

The German beauty, who started dating bodyguard Martin Kristen after her 2012 split from husband Seal in 2012, has recently been in the Bahamas for a sun-soaked break.

Last week she posted a picture of her sunburnt bottom with the word: “Ouch!”

But her latest snap is likely to leave other 40-year-old women feeling sore.