The biggest photo op at the first concert ever at U.S. Bank Stadium Friday will not be the sunset through the super-tall glass doors or the massive Vikings horn.

No, it will be a shot of Luke Bryan’s butt on the giant video screens.

That’s the butt that made him famous. His hit song may go “country girl, shake it for me,” but every country girl at the new stadium will be fixated on his achy, shaky behind.

Just how did Mr. Son of a Peanut Farmer develop his dance moves?

“I never took any lessons,” he said in a recent call from his Nashville home. “I was just a child of Michael Jackson and MC Hammer. Whatever I learned dancing in my bedroom is what I take to the stage these days.”

He’s not sure what that is, though, because he’s never watched a video of his derrière in action.

Bryan is less shy when asked about being the first concert headliner at the $1.1 billion Vikings stadium.

“It’s pretty flattering and amazing,” said the reigning CMA and ACM entertainer of the year, who last summer rocked sold-out TCF Bank Stadium in Minneapolis. “That I can be the inaugural music act there is something that I’ll never forget.”

He knows his stage will be turned over on Saturday to Metallica, those heavy metal kingpins, but he won’t stick around.

“I grew up liking me some Metallica, so it’s pretty amazing that they’re coming on after me,” he said. But he’s heading to a gig in Calgary, Alberta.

Turning 40

The Georgia-born Bryan turned 40 last month. He’s not slowing down, but “I’ve got a swollen knee and some cartilage out and I’m getting my legs and calves wrapped. Jumping on stage two hours a night, four nights a week is pretty grueling. You’re only as old as you feel. So I’m trying to not feel 50.”

Does reaching the big 4-0 mean the uncrowned king of bro-country, who practically made it mandatory to sing about beer, babes and pickup trucks in the same song, will start crooning more serious songs?

“I’ve done that,” he said, pointing to “Drink a Beer,” a melancholy reflection on the unexpected death of a loved one that landed at No. 1 in 2014. “I get pinned as only the party guy. I wake up and I try to write fun songs, deep songs, love songs. But I don’t want to be 55 and talking about girls dancing all over you.”

Bryan has certainly experienced lots of loss in his life. His brother, Chris, died in 1995, and his sister Kelly passed in 2007. Seven years later, her husband died. So Bryan and his wife, Caroline, began raising their nephew, Tilden, now 16. They also have two sons of their own, Bo, 8, and Tate, 6.

“They’re all brothers in their minds. They pick on each other. They love on each other. Til has taught them so many aspects of being a boy.”

Although Bryan’s life has been burdened with some heavy things, he tends to pro­ject a lighthearted personality. He’s known for yukking it up with his pal Blake Shelton, with whom he’s hosted the ACM Awards for three years.

Earlier this summer, Shelton tweeted that he was running for president, with Bryan as vice president and Adam Levine, his fellow coach on “The Voice,” as his “bitch.”

Said Bryan: “I would try to get in there and dethrone Blake and have an internal coup.”

He’s joking. The singer isn’t interested in any power grabs.

“I’m not much on politics,” he admitted. “I like to stay in my lane.”

Business degree

Thomas Luther Bryan grew up on a peanut farm in tiny Leesburg, Ga., hometown of San Francisco Giants star Buster Posey and 2012 “American Idol” champ Phillip Phillips.

Just as the aspiring 19-year-old country singer was going to move to Nashville, his older brother was killed in a car accident. So instead Luke went to Georgia Southern University, where he earned a degree in business administration. Still, his father urged him to go to Nashville to pursue his music dreams.

Bryan started as a songwriter, co-writing “Good Directions” for Billy Currington. His own debut single, “All My Friends Say,” went to No. 5 in 2007 and landed him on the Grand Ole Opry. His sister organized more than 100 friends and relatives to go to Nashville for the occasion and several days later, she died unexpectedly at home of undetermined causes.

Nonetheless, Bryan carried on, scoring a string of hits including party tunes “Country Girl (Shake It for Me)” and “That’s My Kind of Night” and romantic ballads such as “I Don’t Want This Night to End,” one of his 15 No. 1 country hits. His most recent triumph, “Huntin’, Fishin’ and Lovin’ Every Day,” captures the essence of the Cabela-sponsored country superstar.

Farm tour

Bryan got lumped in with the bro-country movement, a term coined by a writer for New York magazine, referring to white, tattooed dudes who sing about trucks, partying, drinking and young women in tight, skimpy outfits.

Bryan took offense at the term.

“I guess the critics and all that have to have a label for successful moments in music,” Bryan said, revisiting his beef. “It’s frustrating for me. All I know, I wrote the music that I felt people would enjoy.”

Claiming that he gets “wrongly classified as a one-trick pony,” Bryan throws in covers of all kinds of music in concert. “If I can make a fan with a Jason Derulo song or a Flo Rida song, I’m not scared to do it,” he said.

He acknowledged that he’s a Prince fan and pointed out “I’ve always thought ‘Raspberry Beret’ was nothing but a country song.”

Make no mistake, Bryan is no hat act.

For six years he played the eternal frat-boy card by releasing a spring break-themed EP in March with such original songs as “Sorority Girls,” “I’m Hungover” and “Take My Drunk Ass Home.” This year, however, he’s exploring a more industrious endeavor with a farm-themed EP series, starting with “Here’s to the Farmer” in late September.

“Am I the most countryest person on the planet? No. But I grew up in a town of 200 people, working in agriculture and hunting and fishing all my life,” he explained.

To walk the walk in his cowboy boots, he’ll perform concerts on eight farms in October in such rural spots as Prairie Grove, Ark., Greenback, Tenn., and Gaston, S.C. Don’t think fans at those barn dances will be able to see him shake his butt on the big screen.