Police are investigating high school students who shared a photo of two Grandville, Michigan teens engaged in a "sex act." The photo, according to cops, also shows four teens watching the act. Grandville teens on Twitter say it's a blowjob "selfie."

The photo got passed around Facebook, Twitter, and Instagram this past weekend, along with denigrating comments about the main girl featured in it. Cops are now warning Grandville parents that their kids could face child pornography charges for sharing the photo. Police Captain Kim Koster told MLive, "No one should be sharing them."

Grandville School District officials wouldn't say if the teens in the photo are students. Grandville students on Twitter, however, are worried that the photo hurts the high school's reputation.

Koster says the investigation into the photo and who shared it is ongoing: "The concern right now is the age of the people involved, consent is also an issue at times as well, so those are some things in any investigation like this one we'd have to determine." It's not yet clear who first shared the photo online, or if the sex act was even consensual.

[Photo via Fox 17]