Daniel Radcliffe’s always too busy acting up a storm to check out the latest YouTube sensations – so the first time he heard the vocal stylings of teen heartthrob Justin Bieber, he had no idea it was a mini-man and not a young woman who was serenading him.

Ouch. Let the Twitter threats begin…..

“I only heard Justin Bieber for the first time two weeks ago,” the Harry Potter star told MTV News. “I genuinely thought it was a woman singing. I’d never heard it before. Is it big in England yet? I’m so out of the loop when it comes to pop culture that I kind of don’t even try anymore,” Dan confessed.

“I know who Lady Gaga is. I think she’s kind of amazing. She’s really got a voice. My God. Not my kind of music, particularly, but she can really sing.”