To backtrack a little, Rihanna's makeup line, Fenty Beauty, dropped a luminiser called Body Lava in March. The product gives skin a dewy shine and glow.
Debuting Body Lava, Rihanna posted a video on her social media pages, showing her squeezing some out on her shoulder and sexily buffing it out with a brush.
People have since been getting creative and sharing their own versions of "body lava on a budget", if you will.
Basically, people are slathering random products on their shoulders and using everything from their hands to brooms to "buff" the stuff in. Some are calling it the #RihannaChallenge. It's weird and delightfully funny:
Rihanna hasn't publicly addressed any of the videos, but she did "like" this mashup on Twitter, so odds are high that she has a good sense of humour about the whole thing.
Regardless, we're suddenly in the market for some Body Lava...