Fans have been wildly speculating over the cause of Bradley Cooper's split from Irina Shayk, with many saying his chemistry with Lady Gaga is to blame.
While that may be a stretch, it turns out A Star Is Born - which Gaga and Cooper starred in together - did have a part to play, as it made Cooper "emotionally absent".
According to People, the actor was distant from Shayk during the long filming period and it took its toll on the relationship.
"They tried to save the relationship but it had changed," an insider said.
A source told CNN that Cooper was intense and focused while creating the film and said: "When he does a role, he stays in character - at least partly - all during filming."
The source added: "He's into bettering himself, and his career and doesn't want distractions".
Cooper himself, acknowledged this toll when he thanked Shayk for her support at the BAFTAs earlier this year.
He said: "I have to thank Irina for putting up with me for all the music I was trying to make in our basement for a year."
While neither Cooper, Shayk or Gaga have commented publicly on the reason for the split, Gaga has shut down rumours of the pair's romantic involvement in the past.
After hers and Cooper's Oscars performance of Shallow set tongues wagging over their on-stage chemistry, Gaga set the record straight with an eye roll.
She told Jimmy Kimmel: "People saw love and guess what? That's what we wanted you to see. This is a love song. Shallow, the movie, A Star Is Born - it's a love story. We worked so hard. We worked all week on that performance.
"From a performance perspective, it was so important to both of us that we were connected the entire time. Look, I've had my arms wrapped around Tony Bennett for three years touring the world. When you're singing love songs, that's what you want people to feel."