Till death do us punch.

A ritzy Manhattan wedding rehearsal dinner descended into a brawl after the groom’s parents objected to a toast on the eve of the couple’s $325,000 nuptials at The Pierre hotel, according to a lawsuit between warring would-be in-laws.

At some point during the chaos, the seething bride gave her betrothed an ultimatum: “Make a choice, me or your mother,” according to a source.

Apparently, he chose his mom, because the ceremony was canceled, he sued his bride, and the father of the bride sued his would-be in-laws.

The bride’s brother said the ultimatum “never happened.”

On Oct. 28, 2016, the night before Bradley Moss and longtime girlfriend Amy Bzura were to tie the knot, Bradley’s parents, Robert and Wendy Moss, hosted the meal at Blue Water Grill in Union Square.

But the parents took offense as the bride’s brother, Adam Bzura, was about to make a “heartfelt toast” and video tribute, says the Manhattan federal court suit filed by Amy’s dad, Bruce.

Robert Moss, 65, “inexplicably and angrily declared that Adam was not allowed to speak at the dinner,” and then growled, “Do you know what I can do to you?,” the suit claims.

He threatened to kick Adam out, and “events began to escalate,” it says.

Wendy Moss, 60, began arguing with Adam, and the groom’s brother, Michael, slugged Adam in the kisser, according to the suit.

The groom’s dad then tried to charge Adam, while Bruce Bzura, 66, struggled to hold him back, the suit says.

The evening ended in “shouting and tears” — and the groom’s mom phoning guests on the spot to tell them the big event was off, according to the lawsuit.

But the nightmare was just beginning.

To make sure the relationship was dead, Robert Moss, owner of Long Island Pipe Supply, threatened to toss his son from the business and cut him out of his will if he went ahead and married Amy, the suit claims.

The Mosses then changed the locks on the East 54th Street apartment Amy and Bradley shared, preventing her from getting her belongings, the suit claims. The Bzuras filed for a court order to allow Amy back in.

The night before a hearing on the order, the Mosses relented, only to allegedly humiliate Amy by mandating that “an off-duty police officer . . . accompany her to pack all of her belongings,” according to the suit.

In the romantic death blow, Bradley, 32, sued Amy, 27, for the $125,800 engagement ring he had given her. The case is pending.

But neither of them appears to be pouting.

On Facebook, a bikini-clad Amy can be seen posing poolside with her family. There is no trace of Bradley on her social media.

Bradley did not take his Facebook photos of Amy down, but there is no mention of the nuptials that never happened.

Like everything else between the Mosses and Bzuras, the bill for the canceled $1,100-a-head wedding reception is in dispute.

Bruce Bzura, head of Old Bridge Chemicals in New Jersey, which posts annual sales of $17 million, claims that he was paying most of the tab but that Robert Moss agreed to cover the $89,919 cost of his side’s 79 wedding guests. Bzura’s suit seeks payment.

“He promised to pay his share, and now he won’t pay a penny,” Bzura said.

A lawyer for Robert and Wendy Moss called the suit’s claims “bogus.”

“We look forward to answering these baseless allegations,” said the lawyer, Michael Antongiovanni.

Additional reporting by Dean Balsamini and Caroll Alvarado