When it comes to their backsides, most women’s deepest wish is to downsize. Jen Selter isn’t most women.

“If anything,” says the 20-year-old New York native, “I’d like to make mine a little bigger.”

That’s right — for Jen, a big butt means big bucks. The fitness junkie has become an Internet phenomenon, turning her hobby of sharing selfies of her perky posterior into a lucrative career.

“I was putting up photos of myself at the gym and started getting a lot of likes,” says Jen, who now has nearly 3 million followers — including Rihanna and basketball players Amar’e Stoudemire and Shaquille O’Neal — on her Instagram, Twitter and Facebook pages and can earn $60,000 just for posting product endorsements. “I just went viral.” 

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Before she was a social-media darling, Jen was just a girl from Long Island with an ordinary behind. 

“I didn’t get attention for my body,” says the 5-foot-6 brunette, who worked at a local gym after graduating high school. “I never had a great butt or one that stood out.” 

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That all changed three years ago, when she started a rigorous diet and fitness routine that focused on her glutes.

The obsessive discipline paid off, and inspired Jen — who lives with her mom in Manhattan — to develop a line of upcoming fitness DVDs. 

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She’s even in the process of getting her most valuable asset insured. 

“We’re figuring it out,” says Jen, who says she has “no idea” of the dollar amount yet. 

But don’t expect to see Jen, who is single, baring all anytime soon. 

“Never,” says Jen, who sticks to yoga pants, leggings and the occasional thong or bikini. “I like to keep my photos classy.”

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Maybe so — but her belfie (butt selfie) obsession has made Jen an easy target for online bullies. 

“People accuse me of being too skinny and ugly every day,” she says. 

But big paychecks and other perks (“I get sent free things, like bikinis and protein bars!”) take the edge off. 

As does feeling like she’s making a difference, one booty at a time: “I love knowing I’m the reason people push themselves off the couch to go to the gym!”

By Nicola Miller, with Hilary Sheinbaum

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