What's going on in his head?

Been dating this guy on and off almost a year. He never made it official. Anyway, he would be gone longer than he stays. So, I ain't seen him in like two months and he lives very very close by. He sees my sister @ the store and tells her to tell me to holla @ him. I did on a myspace message. So the dude reads it and doesn't reply. I know cause I checked the status. No reply or effort to contact me whatsoever. WTF he told me to get at him and when I do he brushes me off? WTF?! Is he giving me the runaround? What sick emotional game is he playing? UGGGGHHH.