Be patient or kill him? ?

I am having a hard time with the definition of dating. I am not stupid by any means, but I am confused as to what is expected of me. I have been "seeing", "dating", "talking" to a man for almost three months now. We have never really been on a "date" per-say, we just started hanging out and spending entire weekends together. He started taking me to his mothers house to do the weekly shopping thing in the third week. I was a nervous wreck thinking that this was a huge step. His mother and I have since become close as we spend every Sunday with her (she is almost 80 and doesn't drive). He calls me everyday, I make sure that he is the first to make contact. When he doesn't call me, he is IM'ing me as soon as he walks in the door telling me of his plans, where he has been and what he is doing, EVERYDAY! All unsolicited I might add. OK, here's where I may have screwed up... three weeks ago I asked where this relationship stood. You know, are we seeing other people, are we exclusive, are we just friends... I have had other opportunities present that I had turned down not knowing if I was in a "relationship" or not. His answer was this... "I am not ready for anything serious right now. I like you, I like hanging out with you" which to me sounds like it is a casual thing, right? But everything else he is doing is screaming "relationship"!! I know it's not about only , because there are weekends where we just hold each other and cuddle without . I have tried to back off, thinking maybe he needed to think about it for a while, but then he just gets pissy with me and says things like "You are the only thing in my life that makes me smile... I don't want to not see you" but then says "I am not ready to be exclusive with you" WTH?! Can you see why I am confused? What is it that he is expecting of me? What am I supposed to be doing? Or am I doing everything I am supposed to already? I am so lost on this term "dating".... please help! Thank you in advance from me, the relationship retardo....