Is he thinking of proposing or is he messing with me?

Ladies I need your advice! As of late my boyfriend uses any opportunity to say. " we should get married!" He said that after I made him an exaggerated breakfast the other day.. I said, "are you asking?" He said yes.. I feaked out because he was serious but I know he wasn't... Idk I guess cause it was random. So i said ask me again when youre serious.... Ughh idk....

So two days ago we were at the post office and I was walking up the stairs and he said.. " imagine if I propose right now while you're going up the stairs and you turn around and I'm on my knees.". I just laughed and he kept walking and the conversation ended.