Is the new sexy Instagram pose unsanitary?

Elise Solé
Spencer Pratt is calling out Sofia Richie for the latest Instagram craze. (Photo: Sofia Richie via Snapchat)

Spencer Pratt is dispensing health advice for social media users — including Sofia Richie — jumping on the latest online trend: Stop putting your fingers in your mouth.

On Monday the reality star tweeted, “Girls putting fingers in their mouths for content is unsanitary and should stop.”

Pratt also subtweeted a photo of Richie with her finger in her mouth and addressed her boyfriend Scott Disick by his nickname. “Lord please tell yo gurl this not healthy.”

The selfie pose in question is called “fingermouthing” and entails people lightly touching their lips with their fingers. “I call this a ‘posed pose,’” Susan Constantine, a body language expert who trains law enforcement and the Department of Defense, told Yahoo Lifestyle in August. “It’s very deliberate. Any time someone puts their fingers to the mouth, it means that they’re holding back in some way. But when the mouth is slightly open, like we see here, it’s an attempt to attract someone.”

So it’s trendy — but is it dirty? Let’s start with an unsettling truth: Ninety-five percent of people don’t properly wash their hands after using the bathroom, according to a study conducted by Michigan State University. The research also found that only two out of three people use soap, and one out of 10 doesn’t wash hands at all.

The problem with that: Traces of fecal matter then attach themselves to surfaces we touch regularly like doorknobs, shopping carts, sponges, food, drinks, and phone keypads. And in certain cases, that can spark nasty respiratory infections and diarrhea (sexy!).

For a visual, according to the Centers for Disease Control and Prevention (CDC), 1 gram of human feces — the weight of a paper clip — can harbor 1 trillion germs.

So do we all need to walk around wearing latex gloves? No. But there’s value in scrubbing up for 20 seconds each time you’re at the sink (per CDC recommendations) after using the toilet and communal spaces.

And it’s probably wise to avoid placing your fingers near your mouth, unless you’re eating. Maybe that’s the next Instagram craze.

Read more from Yahoo Lifestyle:

Follow us on Instagram, Facebook, and Twitter for nonstop inspiration delivered fresh to your feed, every day.