"I reached out to him about doing 'Birthday Cake' because that's the only person it made sense to do it with," Rihanna explained to Ryan Seacrest on Thursday morning when she called in to his KIIS-FM radio show. "Just as a musician, despite everything else, that was going to be the person."
In other words, Rihanna felt that her former boyfriend was simply the best man for the job.
"You know, I thought about rappers, and I've done that so many times, and the hottest R&B artist right now is Chris Brown," she said. "So I wanted him on the track, and then in turn he was like, 'Why don't you do the remix to my track?' and it was a trade-off."