I have never had a boyfriend but there is this one guy...?

So there is this guy. We have been very good friends for the past 2 years now and we are both really comfortable together. He is a flirt with other girls and I see it all the time but he never acts that way towards me. Lately we have been spending more time together and he has asked me to go to lunch with him twice in the last week! We have went to the sae place and sat at the same table and both times we were so comfortable together and we sat and talked to each other for 2 hours each time. He always asks me about girls and what i think about guys and ask for my views and opinions on things. On the walks down to lunch he would ask me about my future and things i would like to do etc. Whats funny, i am usually the one to give people advice on this type of thing and the advice i give usually works, I don't know how because i know nothing about love, but it happens! Now that i am the one in the situation i don't know where to go for advice! Some people have told me to tell him how i feel and see what he says, that's all well a good, but what if he doesn't feel the same and then we are left trying to stay friends well all the while knowing that there is a brick wall between us, eventually the friendship would end and i don't want that. If i have to keep my feelings hidden to keep him as a friend then i will but i just want an outsiders opinion on the whole thing! :) (by the way, we have been told before by numerous people including teachers, that we would make a lovely couple, we have also been asked if we were dating, people were shocked when we said no) everyone always says that we are like a married couple the way we get on! <3 :D opinions please!!