ive been threatened at work and i cant tell if hes joking

i was sitting in a booth folding napkins like a good boy (im so sorry) at work when my coworker walks in. there was a vacuum right outside one of the doors, so he almost ran into it. he trips over it, yells what the fuck is that, and looks around to see who saw. i was the only one that saw. i walk over to a table to clean it off as does he. he leans over the table and proceeds to says that if i tell anyone he got scared of a vacuum hell slash my car tires. i dont have a car but im still scared hell slash my tires. hes done it and a couple of other things to people before, so I cant really tell if he was joking. i just looked at him concerned and then wiped down the tables without saying anything else.