I’m not a rabbi (and if I was, I dont think it would help you ;)) so nothing I’m saying here has any real backing, but I think you have a much easier time if hes not jewish, (I’m not saying its ok, because I really dont know) but one thing to consider a chillul Hashem factor, will anyone in your office think less of jews because you poke fun at your boss? 🙂
you should really try to find out, I’m curious what you’ll get back and its probably important 🙂