Man’s best friend turned into wife’s worst nightmare.

Jennifer Flavin filed for divorce after she and Sylvester Stallone had a massive fight over their new Rottweiler, sources told TMZ Wednesday.

Stallone apparently wanted the pooch, whose name is Dwight, for “protection for their family.” However, Flavin wasn’t on board with adding another dog to the family.

Instead of compromising, they “fiercely stuck to their positions.”

The damning dog argument allegedly led to “an extremely heated argument that brought up other issues” in their marriage, although they didn’t appear to be “marriage-enders” at the time.

Unfortunately for both Flavin and their marriage, the “Rocky” star won the argument and used the dog to promote his new show, “Tulsa King,” by naming him after his character.

Stallone’s rep didn’t immediately return Page Six’s request for comment.

Dwight was reportedly the straw that broke the camel’s back in their marriage.officialslystallone/Instagram

Dwight was reportedly the straw that broke the camel’s back in their marriage.officialslystallone/Instagram

“So incredibly happy with my newly acquired four legged friend ‘DWIGHT’ my characters [sic] name from the Series, keep punching and keep barking !!!” Stallone wrote in an Instagram post announced earlier this month.

Stallone’s other dog, Butkus, the famous bullmastiff from the “Rocky” franchise, may have also been a factor in their marital problems after the actor covered a large tattoo of his wife’s face with a pic of the pup.

Sylvester Stallone previously sparked breakup rumors when he put his other dog in front of his wife’s tattoo.Facebook

Sylvester Stallone previously sparked breakup rumors when he put his other dog in front of his wife’s tattoo.JOHN BARRETT

Sylvester Stallone previously sparked breakup rumors when he put his other dog in front of his wife’s tattoo.Instagram

On Aug. 19, Flavin filed to dissolve their 25-year marriage in Palm Beach County, Fla., Page Six confirmed Wednesday.

In the court documents obtained by Page Six, the former model claimed their union is “irretrievably broken.” Flavin also alleged that her hubby has “engaged in the intentional dissipation, deplete and/or waste of marital assets.”

Jennifer Flavin filed for divorce last week.GC Images

“I love my family. We are amicably and privately addressing these personal issues,” Stallone told us on Wednesday.

The “Creed” actor wed Flavin in May 1997 after they met at a restaurant 10 years prior. The former couple share three daughters: Sophia, 25, Sistine, 24, and Scarlet, 20.

Prior to Flavin, Stallone was married to Sasha Czack from 1974 to 1985 and Brigitte Nielsen from 1985 to 1987. He and Czack shared sons Sage, who died in July 2012, and Seargeoh, 43.