(Cover) - EN Showbiz - Rihanna has joked she was "sick to [her] stomach" after one of her Battleship co-stars sang her hit What's My Name at karaoke.

Brooklyn Decker has recalled how she belted out the track while the Battleship cast were at karaoke bar in Tokyo. Afraid she would be judged by the song's creator, she grabbed the microphone while Rihanna was not present.

Rihanna is upset Brooklyn felt too uncomfortable to sing the tune in front of her.

"I'm sick to my stomach. Nothing else matters," she told MTV News, in a joint interview with Brooklyn. "You betrayed me."

Brooklyn explained the castmates did karaoke to honour the Japanese culture. But she felt she did not do the song justice.

"I mean you're in Tokyo. It's like the origin of karaoke, so we felt like we were being true to the culture," she explained.

"It wasn't for a bonding experience. It was respect. We were respecting the Japanese culture. No, no fun!

"OK, so it was before Rihanna got there. So, I sang [Rihanna's] What's My Name. But I rapped the Drake part. I'm sorry. But I had to it before [she] got there because I felt like I was putting the song to shame."

Rihanna, on the other hand, prefers to sing tracks other than her own when she's at karaoke. While she performs for a living, she admits she gets nervous.

"Yes I do [karaoke], but under very specific circumstances," she said. "I have to be a least tipsy-ish and I have to be with my assistant, who is my karaoke partner. We like to sing Bon Jovi and Journey. Anything that's loud and you get to sing and pretend you're a rock star." (C) Cover Media