Their chemistry is undeniable ... so it's no surprise there's speculation Lady Gaga and Bradley Cooper are having an affair.
And the two A Star Is Born co-stars further fuelled the fire with their steamy performance of Shallow at the 2019 Academy Awards.
But, while Gaga continues to deny the rumours, new reports claim the 44-year-old actor's relationship with supermodel Irina Shayk is on the rocks.
It's believed things aren't "good" between the pair - who have been dating since 2015 - and that they're only staying together for the sake of their two-year-old daughter Lea De Seine.
A source told the New York Post: "Because of their daughter, they keep trying. Things are not good. Neither one is happy. The relationship is hanging by a thread."
Of course, the reports have sent the rumour mill into overdrive, with A Star Is Born fans instantly making assumptions the chemistry Cooper had with Lady Gaga had something to do with his relationship breakdown.
Speaking on Jimmy Kimmel Live about their Oscars performance earlier this year, Lady Gaga revealed that she and Cooper are just good friends.
"People saw love, and guess what? That’s what we wanted you to see."
"This is a love song ... The movie A Star Is Born is a love story … We worked all week on that performance."
"He laid it all out. Everything that you saw — the way that it was shot, the way that they pushed the piano out [and] you saw them put the piano together, us walk up on stage, no intro — that was all him."
"It was so important to both of us that we were connected the entire time… When you’re singing love songs, that’s what you want people to feel. I’m an artist, I guess we did a good job, and, fooled ya!"
And it seems that's exactly what they did!