What does this mean?! Friend situation!?

I have a guy friends and I have known him since the beggining of the school year. We are very good friends and I am thinking of asking him out. One problem and I don't understand this is that we only talk before algebra, during lunch, before the second half of algebra. (lunch is in the middle of algebra) We see each other several other times, walking by each other in the hall. We never have time to talk in the hall we have like 5 seconds but that's enough to say hi or sup. We don't. I don't know why, its like we don't know each other! Why is this? Do you think I should ask him out? Thanks everyone!