An elderly private-equity honcho has been trolling his estranged wife so much by text  — including over Donald Trump’s election win — that it helped send a Manhattan judge over the edge Tuesday.

John H. Foster, 82 — a longtime health-devices mogul and managing partner of the $800 million private equity firm HealthPointCapital — fired off the slew of phone messages to wife Stephanie in the past two weeks, including while she was testifying in court just feet from him, the judge heard in the warring pair’s divorce case.

“Happy Halloween,” read one of the texts that John wrote to Stephanie while she testified in court Oct. 31 — and he even threw in a few “pumpkin and ghost emojis” for good measure, according to one of her lawyers, Rita Glavin.

John H. Foster, 82, trolled his estranged wife, Stephanie Foster, with so many text messages that it sent Manhattan judge Ta-Tanisha James over the edge Tuesday.Gregory P. Mango

But at the end of the seemingly innocuous seasonal greeting was a foreboding premonition.

“What goes around… COMES AROUND!!” read the text, as described by Glavin in court Tuesday.

John — who has claimed during the former couple’s three-year-long divorce trial that he is now destitute — also sent Stephanie a text after last week’s presidential election with a cartoon image of President-elect Trump holding his fist in the air.

The hubby wrote, “you OK? Because you didn’t look well today,” Glavin said.

“That is not about, ‘I’m concerned, I’m worried about you,’ ” the lawyer argued, “That’s a taunt to a witness in the middle of testimony.”

Glavin, a former federal prosecutor-turned-criminal defense lawyer, called it “witness tampering” and cited disgraced crypto wiz kid Sam Bankman-Fried, who was locked up for intimidating witnesses last year.

One of the texts read as “Happy Halloween,” including a few “pumpkin and ghost emojis” for good measure, according to one of his estranged wife’s lawyers, Rita Glavin.Gregory P. Mango

Foster’s lawyer, Linda Rosenthal, attempted to classify the texts as an example of John’s concern for his wife’s well-being, but Judge Ta-Tanisha James didn’t appear to buy it.

The Manhattan Civil Court judge ordered that neither party in the acrimonious matrimony is allowed to text the other, “or else there will be sanctions.

“And that starts now,” James said in a stern tone.

John and Stephanie Foster married in 2009 and led an extravagant lifestyle filled with jets, a $10 million Fishers Island home, a sprawling Texas ranch filled with exotic African animals and a pricy Fifth Avenue pad.

Stephanie says that despite her husband’s claims of poverty, a damning text message she found, as revealed in an article published by The Post, is evidence that his claim of destitution was part of a “net-worth strategy” to leave her penniless after nearly 15 years of marriage.

James’ frustration with John on Tuesday over the texts turned into yelling when it surfaced that he’d been missing months of payments for his wife’s rent and other expenses.

“So let’s get that done — today,” James boomed at Foster and his legal team.

“Ms. Foster’s rent is to be paid. Spousal support is to be paid.

“You will not keep Ms. Foster from receiving the monies this court has already ordered,” James continued from the bench.

“That bothers me.”

“It feels like gamesmanship is going on,” the judge said, “and I know that’s not what’s occurring, but that’s how it feels.”

The hearing ended early when Foster suddenly left the court room complaining of chest pains and court officers called an ambulance for him.