Frisky deer is confused when he humps a decoy doe’s head off

Oh, deer.

The Bergan family of Eldorado, Illinois, recently spied a randy buck creeping up on what he thought was a beguiling doe on their lawn.

The resulting sex tape is going viral.

“Oh my gosh, I’m so scared right now,” an unseen child can be heard saying as they peer out the sliding glass windows of their home, located in a wooded area.

“She’s on top of it!” a horrified Lana Bergan, 39, responds as the horny — literally — deer prepares to mount his new lady friend. “Don’t move ’cause he’ll see us. Watch. Watch!”

The amorous action plays out as the song “Hero” — a 2012 hit by the band Family of the Year — provides this romantic soundtrack: “I don’t wanna be your hero / I don’t wanna be a big man / Just wanna fight like everyone else.”

Bergan dissolves into a giggle fit as the creature proceeds to hump to his heart’s content.

That’s when things go hilariously awry.

Turns out Lana and her husband, Rostin Bergan, 40, are avid hunters.

“This nice buck was interested in our doe decoy,” Lana tells the ViralHog video agency. “He pursued her until her head popped off.”

Meanwhile, the devastated deer is merely left to stare in heartbroken disbelief at the decapitated head of his lover on the lawn.

But the hunting community has embraced this tragicomic romance, with sporting goods company Nose Down Scents’ Facebook page alone racking up more than 70,000 viral video views.