In the photo, Heidi is crouching on the floor in a black thong and she looks amazing! She added a star filter to the sultry pic.
Heidi is known for baring it all. She regularly sunbathes topless with her boyfriends.
Maybe this latest photo was a gift to her young lover, Tom Kaulitz, who she's been seeing for the past few weeks. The two were recently spotted making out on a beach in Mexico.
The Project Runway host split with boyfriend Vito Schnabel last year.
On Insta, Heidi's become the selfie queen, posting a series of pics of herself using the starry filter.
What do you think about Heidi's thong selfie? Let us know in the comments!