This affair was may have been in fashion, but it was way out of tune.

Thanks to wild Instagram video and photos, one Airbnb host found out that a temporary tenant’s photo shoot — with a high-profile fashion model — caused pricey damage to her $120,000 grand piano.

Fashion designer Mikhael Kale rented a swanky Paris apartment for €1,000 euros a night during that city’s Fashion Week in September.

Apartment owner Gina, who asked to be identified only by her first name, said the Canadian-born Kale told her he needed the apartment to chill as he prepped for his post-apocalypse-themed fashion show. She told The Post that the designer promised there would be no social events at the home unless he worked it out with her in advance. 

“There will be absolutely no gatherings of any sort,” Kale assured her in a written statement, according to Gina.

He also agreed to her rule that the piano remain covered when not being used, Gina said.

But after Kale checked out, Gina alleged that her house cleaner noticed that the piano’s cover was put back wrong and that the instrument’s black lacquer finish had been heavily scratched.

Gina then looked at…