What does it mean when a guy flirts under his breath?

[Anonymous]

I’ve caught my co-worker who I have a little crush on say a few flirtatious things after I would say something. For example, one time he was dancing and mentioned that he isn’t that good because he has a pudgy stomach, and I told him that I have a pudge but I can’t dance at all. Then he mumbled something like “You have a nice natural pudge” and I asked him to repeat himself so I could make sure that I heard him clearly but he said nevermind. Then another time this had happened after I sat with him in the breakroom and I let out a sigh because I was hot and tired. He asked me if anything was wrong and I said “Nothing, I’m hot” and he said “What?” wanting me to repeat it (even though I said it loud and clear enough the first time but I repeated myself anyway). Then he mumbled “You are hot.” and assumed that I didn’t hear him. He is nice though and helps me out a lot at work even without me asking. I’ve also caught him staring at me a few times, not in a creepy way, but more like he hope to get my attention type of stare.

[TB51602]

I can't really say fur sure sence I don't know the guy but it sounds to me like he either doesn't know how you'd respond to the comments that cross his mind or he's interested but not sure if you are too...