Okay, Rodney as da Vinci was pure er...genius. John being out of his depth from before the beginning was also great. Rodney too busy being the scientist to do the minutia of his second job, Master Vampire.

This is a real gem.

You must do more of this. And John can find out when he drinks lemonade that Rodney won't get close to him. Because when Rodney was alive he had a citrus allergy and even after centuries he can't stand to even smell it. So John keeps buying lemon pie and lemonade and fresh oranges but they all go bad because for some reason he never gets around to eating them.