LOS ANGELES • Speculation has surfaced again over whether Lady Gaga is responsible for the bad romance between Bradley Cooper and Irina Shayk.

Cooper, 44, who starred with Lady Gaga, 33, in blockbuster A Star Is Born, has split up with supermodel Shayk, according to American media.

But sources told Us Weekly that nothing happened between Cooper and the singer when they acted in the 2018 movie.

The scorching on-screen chemistry was just for show, they insisted.

So what led to the rift between Cooper and Shayk, 33?

They have dated for four years and have a daughter.

According to the Page Six portal, the couple just drifted apart and are no longer happy in each other's company.

"They haven't been getting along for a while," a source told Us Weekly.

The split comes as a surprise to many observers as Cooper had reportedly chosen to spend more time with his family after the frenetic campaigning for A Star Is Born in this year's Oscars race.

Perhaps it was a clash of values and lifestyle.

A source told Page Six: "He doesn't drink and is into spirituality.

"She wants to go out."