Cried at work because I think someone was trying to crawl under my skin.

I don't understand whether people are being serious or humorous, except when they are very obvious about it. That is not perceived very well by socially apt people who don't struggle to communicate on a daily basis. I work in a very high interactive field. I needed something and asked for it from the person whose duty is to provide us with utilities according to the task at hand, and he told me that he has been told by the boss to do the opposite. Even though I had had a conversation with the boss and had been given a clear go ahead for it. I thought maybe they really had a conversation and the boss had changed his mind, or there was some miscommunication, so I asked him if he was sure he had that conversation, he said yes, i asked him if he was very sure he didn't mishear the boss, he said yes I'm telling you. So I said, "well then maybe we can ask him again when he's around before taking the utilities out." He said, yes okay. Then he was starting to turn and leave, while taking off his mask, and that's when I saw the grin on his face. It was....a weird grin. I didn't understand it. Was it a "i'm just joking" grin? Or was it a "I'm making fun of you" grin? I think the latter. And it ruined my whole day. And I just sat in a corner and cried after that.