Confused

There is cute guy at work and I've liked him for a while and sometimes he barely talks to me and other times he jokes around with me and acts like I'm so awesome. He was single for a while so after a long conversation I gave him my phone number and he never texted me then my co worker told me he had a girlfriend. I've felt like it been awkward between us since then for good reason. But Friday he was teasing me about something very flirtiously and it seemed like he was really nervous. I keep feeling like there is something between us and I can't shake this crush no matter how hard I try. Am I crazy for thinking he might have feelings for me? Could he have broken up with his girlfriend? Sometimes I wish I could punch my feelings in the face haha Advice from my friends is that he's just being nice to me. Any thoughts?