A new game played in at least one Minnesota schoolyard is upsetting parents and teachers with its "disgusting" premise. "Rape tag" is just like freeze tag, with one alarming difference: Participants need to be humped to be unfrozen. Here's what you should know:

Wait, wait. Rape tag?

You read that right. At Washington Elementary School in New Ulm, Minn., kids in at least two fifth-grade classrooms were caught playing the game, says Sylvia Wood at MSNBC. Of course, teachers and recess supervisors were quickly instructed to talk to their students and put a stop to the game. Principal Bill Sprung then sent a letter home to parents cluing them into what had happened.

What did the parents say?

They were not pleased. Sprung says 15 to 20 parents have contacted him, "some of whom were upset about having to discuss the sensitive topic with their children," says Wood. Sprung says he sent the letter "to quell rumors and speculation," and thinks his staff has done an "excellent job" of "extinguishing the game." No kids have been spotted playing rape tag since he sent his letter.

How did kids even come up with this game?

"Likely the children at this school didn't understand what rape means," says Amy Graff at SF Gate. But in a way, that's what make this story so "unsettling." The kids probably picked it up from television or the internet, and assumed that "humping and sex is weird and silly" — as children tend to do. "It's just upsetting that kids are familiar with the word rape at such an early age, whether they understand it or not." Well, "kids are known for pushing the offensiveness envelope," says Anna North at Jezebel. Let's hope these particular youngsters learned their lesson.

Sources: Babble, Jezebel, MSNBC, SF Gate