Women are posting selfies of themselves in a dangerous belly button-related challenge.
The idea behind the challenge is that you try to touch your naval by swinging your arm around your back.
If you are slim enough, you should be able to reach your belly button and snap a picture.
But if you can't, it apparently means you need to lose weight.
Thousands of people in China are posting selfies of themselves completing the challenge on Weibo, the Chinese version of Twitter.