Ex boyfriend troubles

So ive recently reconnected with my ex and I’m enjoying things and we have been slightly flirting with each other other text. we will be in the same city together soon for separate holidays but he wants to catch up and do stuff with me while we’re both in the same city and always brings it up with me. But I also have the sense he is talking to this other girl that I think he’s seeing/dating but not committed. he’s getting very comfortable with me lately, maybe too comfortable and I’m just confused if I should hang out and maybe know what he’s thinking/doing because he’s very keen to meet up with me. He could just be playing me though or using me.