Help me! Confused because of my ex's attitude?

Ok so I have this ex we broke up more than a year ago and I asked him in a nice way not to talk to me anymore. He did and he has done ever since, mostly via text, we re not always talking but normally we are. I take in average like a week to reply to his texts and he normally replies after a couple of minutes or hours at the most, and sometimes even though I have not even opened his inbox, he sends me another message like a couple of days after he sent me the first one. I ve only seen him once since our break up, we went for food but he paid for him and I paid for me. Nevertheless, he s always asking me if I ll go to concerts or places he will go, so we can see each other, and if I say yes I will go, he asks me with whom I ll go and like a lot of questions. Though I m always telling him we should go somewhere and he says he s busy. Why is he acting this way?