When writing to a celeb, is it more proper to address them as "Mr. SoNso" or by their first name? The celeb I'm getting ready to write is 20 years my senior, however I'm not a child either so I'm questioning which way I should do it. I don't want to seem disrespectful, when meeting him in person I would probably address him by his first name.....that is if I could even speak at all if I met him. Knowing me my tongue would get all tangled up and I'd sound like an idiot.

I've read many of the other helpful hints on this website about writing but I haven't run across any topics that address this question. Any helpful hints are appreciated.
