Thanks for the advice, HowlerKarma. I'm finding this a difficult one to solve.

I will be hated for admitting this, but my son has never had tantrums. He has always been a calm, sensible baby/toddler/child. Even when he was three and four he could play Uno and handle losing. He is so mature, and has amazing self-discipline and self-control that I admit that I actually like seeing this side of him, it makes him more human (and like my little baby :))

I just don't like how bad it makes him feel; I also don't want him to be rude on the day. I am hoping that he will realise he's not at home, and that he will act accordingly to beloved rules lol.