Stella Maxwell
Stella Maxwell attends Mat Gala on 1 May 2017 in New York City Getty

Victoria Secret model Stella Maxwell took to social media to wish her close friend, Elsa Hosk on her 29th birthday with a rather revealing photo of the duo frolicking on the beach.

Maxwell, who is dating Twilight actress Kristen Stewart since 2016, uploaded a racy photo, most possibly for a photo shoot, featuring Maxwell and Hosk both wearing a see-through slip. They are seen in near embrace, and Maxwell's behind is completely exposed in the raunchy snap.

"Happy birthday to the girl @hoskelsa ur the koolest, " the model captioned the Instagram snap. Maxwell's rather sultry photo has sent her 3.3 million followers wild with speculations about the state of her relationship with the Personal Shopper actress.

A user commented, "this picture is breathtaking," another wrote, "Gorgeous Girls." The steamy photo has made fans to speculate if Maxwell is still dating Stewart. A user asked, "Are you and Kristen Stewart broken up? I ask because I love your work and am a huge fan of Kristen. And it said online for about a week that you two have not been spotted together. And before then you two were basically inseparable."

Another curious fan commented, "What is up with Stella and caressing girls who aren't her girlfriend." A user even called Stewart lucky and wrote "Omg... you are sooooooooooooo hottttttt.. Kristen Stewart is lucky."

Many users have wished Hosk on her birthday, with one writing, "Happy Birthday lovely Elsa, another saying, "Gorgeous Happy Birthday."

Kristen has been linked to 27-year-old model since 2016 Met gala, and celebrity couple have made numerous appearances together, enjoying date nights and romantic vacation since then.

Most recently the couple was spotted shopping for Halloween outfits together in Los Angeles on 28 October.

Both were seen wearing jeans, with Stewart wearing a vibrant canary yellow top while Maxwell opted for a low-key white colour for the outing.