Harry Potter Co-star Emma Watson PICS

Reveals Harry Potter Co-star Emma Watson: "I mean, yes, I have tried spirits! Of course, I've tried spirits," she said. "We drink at 18 in the UK -- but I'm actually legal to drink now in the US. It's worth mentioning -- I'm 21!"Letterman grills Watson about her relationship with alcohol on Monday night.Harry Potter Co-star Emma Watson PICS