If あなた think they'll find it funny? Go ahead. I had to do the same just to get through the thing without throwing my kindle against the ウォール in frustration. If it's to insult them, then no. Leave it out, even if it's just good-natured ribbing; no need to stir trouble for the sake of it. I don't know あなた または your friend, so its up to you; just giving my thoughts.