Okay, if he's your best friend, you have to behave like a friend! Friends don't play games and act all coy and send emails about something on their heart that needs discussing. If he's a true friend, he's not going to get angry/disgusted/whatever it is you've gotten your worked up imagination creating for you. If he does act that way; he wasn't a friend and could never have become a lover, etc.

Which reminds me of an amusing ditty/greeting card that might make you feel better:

"Beware of friends turned into lovers. . .
They'll steal your heart and then your covers."