Why can he talk to them, but not me?

I work with a guy who I think is absolutely adorable. Since working with him, I’ve developed a sort of crush on him and really want to be able to flirt and talk freely with him, but he rarely talks to me. At first, I thought maybe he was just shy. But my coworkers have all told me that he’s extremely outgoing with them. It has been suggested that he could be intimidated by me and I’ve definitely not ruled it out as a possibility, seeing as I myself am extremely intimidated by him. It’s just that every time I see him, I clam up or feel like my face is on fire. I guess it’s so hard to talk to him because I don’t want to look like an idiot in front of him? I don’t know. I am really bummed by this because I really am a friendly, approachable, and down to earth person. I just don’t understand why he can talk to my coworkers so easily and not to me. Advice?