He let this slip while also revealing that Ke$ha wasn't first choice to appear on his latest subtle love song, 'Timber'.
Having gushed about how great Ke$ha is and how her voice is a thing of wonder etc etc and so on, he then added: "With that said, that was an ironic situation there. The person we were looking at first to work on that record was Rihanna."
"There was something she had to do with Shakira, so she wasn't able to be on the record. Ke$ha is crazy, sexy, cool, wild and fun."