I work in an advertising agency and my boss (who is quite cool) has just asked to be my friend on Facebook. I feel invaded - I'm passionate about my work but want to keep it separate from the rest of my life. I definitely don't want him spying on what I say to my friends. He has also asked other people in the office who have said Yes and they seem to think it's fine. But I don't want to. Can I say No without damaging my career?

Advertising creative, female, 26