We spotted Ke$ha on her way into the BBC Radio 1 studio in London, England, on Thursday, and she rocked a sexy see-through blouse and thigh-high stockings.
While being interviewed by radio host Nick Grimshaw, she admitted having a crush on One Direction star Harry Styles, who was secretly listening to the conversation.
"He has a really good mouth, it's true, I'm not trying to be a weird pervert!" the songstress admitted. She then rated Styles a "10" before finding out he heard the whole thing.
Later Ke$ha told the DJ, "That's the most embarrassed I've been in a long time, good job."
Styles famously dated singer Taylor Swift. He was most recently linked to a British model.