A photo of a Taco Bell employee licking a foot-long stack of taco shells is prompting visceral "ews" throught the Internet - and a social media crisis for the company.

Taco Bell has a wee bit of a PR crisis to address after the charmer of a photo emerged on Instagram.

The pimple-faced teenage boy whose tongue is licking the taco shells is probably going to be fired, but that hasn't helped - the viral photo keeps getting posted to Taco Bells' Facebook page (then removed, then reposted, etc etc).

Anyone who has ever eaten at Taco Bell will probably be thinking twice now (or a third time, because numerous urban legends about the place being dirty already exist...some suspension of squeamishness was already required. This is a reminder that, yup, it's not just an urban legend).

We don't know for sure that the shells were served to customers, or even meant to be (they may have been on their way to the trash, right? Right???)

One Taco Bell rep told the Huffington Post, "When we learned of the situation we immediately contacted this restaurant's leadership and although we believe it is a prank and the food was not served to customers, we are conducting a full scale investigation and will be taking swift action against those involved."

OK, thanks Taco Bell. But we still can't un-see the employee licking the taco shells.