On one night in 2015 in particular, their friendship reached new heights as the frontman invited Bardem and his wife Penelope Cruz on stage during a concert. Bardem absolutely made the most of the opportunity by dressing up in a purple feather boa and cowboy hat while dancing to 'Mysterious Ways'.
Speaking to Jimmy Fallon on his talkshow, Bardem explained how the opportunity presented itself.
"Very simple, Bono says 'Hey guys, since we are playing in Barcelona and you're bringing like ten people, would you like to get on stage?' and I said, 'YES'. [Cruz] said 'no' at the same time. And then I said to Bono, 'the only thing I want to tell you is that if I get on stage, some people may not like it'
"So I put a hat on, I put on a purple boa. I do my most erotic movements as I could imagine, because the song was 'Mysterious Ways'. And then of course the song finishes, I took the hat off and the whole stadium was like 'Booo!'"
The "Dune" actor also revealed that he was responsible for Prince being an hour late for one of his concerts as he invited Bardem and Cruz to a dinner that ran over schedule.
"We took a dessert, we had drinks and I was like 'nobody is coming here to pick us up'. So [after dinner], we were accompanied to our seats and the show started and we were like 'Oh my God! They've been waiting an hour for us to finish our dinner. So that's my Hollywood star story. I'm so sorry."
Bardem won his best supporting actor Oscar for 'No Country for Old Men' that same night, so we'll let him off for that accidental diva moment. It's fair to say he knows how make the most out of his invitations to party with musicians.
In the interview, Bardem also talks about his upcoming role as King Triton in 'The Little Mermaid'. Check out the full interview below.