Do I have to be nice?

So the date for the electrician to come out has changed, again. Big surprise, huh? Well, I just want to know if I have to be nice to him when he does come out. DH said the guy is going to take off his regular job to come out himself and do the work. Errrrrrrr. Now I feel somewhat guilty for that. So I still don't think I'm going to put on a happy face if/when he shows up.