It seems to me he looks up to you as a superior and is challenging you in the way that a young student might challenge a master, as if to say, “Oh, you’re so good, then answer this?” and they test to see how you respond. He might *want* to believe what you’re saying.
Well, you can challenge him on it. Sometimes what I will do is imagine the other person who is goading me on is my best friend and we’re having an argument over a couple of beers. I take what he says literally, without to much interpretation, and go through it, as if he has friendly intentions. Sometimes people can be surprising. I’ve made new friends out of what at first appear to be enemies.