Perhaps its some sort of defense mechanism like others seem to think as well. I always seem to do this around guys who i form close-more-than friendship/friendships (lol coudlnt finf the right word)with. I remember two years ago i met someone who i fell very hard for and we saw each other practically every day. As time went on i started to get suspicious of why he seemed so interested in my friendship given that he was so "out of my league", thus slowly but surely i stopped texting back, calling back, i mustve been such a purposeful bore when we were hanging out that yeah eventually now were not friends anymore. In my head he just saw me as his nerdy sidekick companion, to me he was more than that, but the "league" issue was so ingrained into my head that it was all i could think about when we were together. Maybe next time i wont think that way and wont ruin a friendship(after all that is all there was-to him) over something stupid.