Protesters in the city may chant, “Love trumps hate,” but that’s not stopping some from piling on Donald Trump’s family.

“You can’t be a Trump supporter in the city,” an old Buckley School classmate of Donald Jr. admitted to The Post.

“I wanted to throw a fundraiser for [the elder Trump last spring], and my fiancée was like, ‘Don’t you dare! You’ll never get one ounce of business again in this town,’ ” said the classmate, who has his own hedge fund.

Ever since the president-elect’s win in November, his family’s life in the Big Apple has been turned upside down. With 78.5 percent of city voters casting their ballots for Hillary Clinton, liberal New Yorkers are still waging an anti-Trump campaign — often aimed at his three oldest children, Donald Jr., 38, Ivanka, 35, and Eric, 32, all born and raised in Manhattan.

So what’s it like when your hometown — supposedly the most tolerant city in the nation — turns intolerant toward you?

Donald Jr.’s wife, Vanessa Haydon, who grew up in an Upper East Side townhouse and lives at Sutton Place with five children ages 2 to 9, isn’t handling her newfound pariah status well, a close family friend says.

“It’s not wonderful when you’re being trolled on Twitter, with people saying really bad things and you have five kids. It’s horrible,” the friend said.

In mid-November, eight teenagers heckled a visibly irritated Eric Trump and his wife, Lara Yunaska, outside the Quality Italian restaurant on 57th Street, yelling, “Eric, f- -k your father!” and, “Love trumps hate!

And on a recent Monday evening, some 150 protesters descended upon the Puck Building in Nolita to protest Ivanka Trump. Her husband, Jared Kushner, owns the building.

Artists had crafted signs bearing messages such as “Dear Ivanka: your daddy is scary as hell,” and chanted, “Tell Daddy no,” as they circled the posh building. (Ivanka Trump and Kushner don’t live at the Puck, but rather on the Upper East Side.)

Among those marching were painters Nate Lowman, whose work is reportedly in Ivanka’s personal art collection, and Marilyn Minter, whom Ivanka follows on Instagram. Also in attendance was socialite filmmaker Arden Wohl, a friend of Ivanka’s.

“This is a plea to Ivanka to talk some sense because she’s in this transition committee for her father, and hopefully she can be his voice of reason,” Wohl told New York magazine. “She’s the smartest of the children.”

But all three are resilient, sources told The Post.

One New York media executive who has worked with Ivanka said the three grown children “have the thickest skin I’ve ever seen.”

“During the campaign, I went to Ivanka’s office to review a website, and the top story on the site was a really negative piece about her father accompanied by an unflattering photograph [of him],” he said.

“She just laughed and moved the conversation forward.”

No doubt the president-elect’s children are a bit more unflappable than their late-night-tweeting father.

When Donald Jr.’s Facebook page is inundated with hateful posts, he and brother Eric simply ignore the comments, according to the Buckley classmate.

“But usually, 100 friends come and back them up and say, ‘Go f- -k yourself,’ ” the classmate said.

And despite the lack of love in the Big Apple, the close family friend said that unlike Ivanka — who has announced that she and Kushner will move to Washington, DC, with their children, ages 8 months to 5 years — Donald Jr. and wife Haydon won’t be ditching their Manhattan life for the Beltway.

“No way,” the friend said. “They’re not going to be chased out of their home.”

Trump campaign manager Kellyanne Conway said The Donald’s three eldest children would keep their New York roots.

“They’re living their lives as they always have,” she said. “They’re classic New Yorkers. They love the city, they soak it in — the culture, the cuisine, the friendships.”

Ivana Trump, the first wife of Donald Trump and mother of the three adult children, told The Post in November that while she’s confident her kids can handle the uproar, she worries about Barron, Trump’s son with wife Melania.

“Barron is 10 years old. It’s so new for him. I think [my kids] are around cameras all their lives and are prepared for it,” she said.

(Trump has a fifth child, Tiffany, 23, with second wife Marla Maples.)

“Protests are protests,” Ivana added. “It is a divided country. People on the other side, they just have to get over it, because America voted and that is that.”

But even if New Yorkers don’t love the Trumps, the tourists do.

“Now that the holidays are upon us and the rest of ‘real America’ from ‘flyover country’ is on Fifth Avenue, selfie-seekers, the happy faces, are out in full force at Trump Tower,” Conway said. “They are literally ebullient.”

Trump won and his biggest supporter is mad as hell: