Falling for a straight guy

For the third time I fell for a straight guy. The storyline is the same for all three guys. We will become friends for a random reason, spend so much time togother, talk about things that I don't normally share with other guys, he will start showing "extra" care for me and then it will hit me. Am I falling for this guy? Is it possible that he also like me? Why is he doing these things a normal guy friend would not do to his close guy friend? Should I ask him? He knows I'm gay. He knows I've been through this. So, why?