I read this situation differently to you and a lot of other people here. I think your CEO was testing you for your reaction. It's a confidence test. Or, poss

I read this situation differently to you and a lot of other people here. I think your CEO was testing you for your reaction. It's a confidence test. Or, possibly a "dude" or "bro" test, depending on your CEO's age. You're supposed to match his jocular tone while telling him where he can stuff his ideas on fashion (and his flip flops). Volleying his smack talk back at him as one does to equals sends a signal. As does obediently Yes Sir, Right Away Sir'ing. As does getting offended. As does being embarrassed and humiliated. He wanted to see which of those signals you'd send. (And he's probably not the nicest human being for doing so).