is he into me or I just misunderstood him?

Three weeks ago I've met this guy and he was supposed to help me with some work for my job project. After some talking about my work, we got from friendly discussions to flirts. But this was just on chat, whenever he got next to me he would just talk about my work or something else (I noticed him blushing sometimes), and won't open the subject about our flirts. After one of our last flirts, he stopped texting me as well as the flirty conversations (but he continued to blush sometimes when seeing me and I caught him once starring at me) . Now, whenever I would ask him something he would answer straight away but that's it, only related to work. I could not stand it anymore and I asked him why is he acting like this with me now, and he said he's trying to help me (about work, like nothing happened), etc...but then when i said i was not talking about this, he changed the subject. What is happening? I'm very confused by his reactions.