why is he acting like this?

ok, so me and my ex broke up about 4 weeks ago. and he texted me completely out of the blue and unexpected and he asked why do I give him rude looks when I pass by him and I just said thats just the way I look. and he said ha you never did before. and I said I never looked at you that way before? and he said that I always looked happy and now I look bitc and give off that bit vibe. then he asked about my relationship stuff since we broke up because on my a social site this guy austin is my the first person on my top so he asked so hows your new boyfriend austin? oh wait thats your ex. then he said I always complained about him and I like him again, and on my a social site in the about me section it says I have a boy on my mind so he asked who the boy was and who I like now. why do you think he cares? he acts like he doesnt wanna be my friend so I dont know why he would care. any idea why he would? and at lunch today I was hanging with my two best guy friends and he kept glancing over at me