Most Helpful Guy
No, I don't think he knows you like him, I mean just getting nervous around him and smiling at him are not the only signs that will convince him that you like him so he may not actually know that you like him.
About him liking you, I don't think he likes you. I mean he might be just being himself, he could simply be talking to other co-worker completely unknown to the fact that you like him.
Moreover it's not like you two are going out on dates and it's not like he made it clear to you that he likes you, so jealousy factor doesn't come into play here. I don't think he is trying to make you jealous on purpose. Not in this situation.
However if he was doing the same thing while he was dating you, then yes that would be totally wrong and unjustifiable.