Once upon a time, super-svelte Instagram models were content to simply show off the gap between their thighs.
Now, they are taking it a step further, flaunting the triangle-shaped gap between their upper thighs, a craze the British press has cleverly called "Toblerone tunnel."
It gets its name from the popular premium chocolate snack, which is in the shape of a triangular prism. You've probably had one at an airport.
It's the latest bizarre Instagram body trend to catch on, following in the tradition of the thigh gap, the thigh brow and, more recently, hip cleavage.
See the 10 wildest examples in the slideshow above.