Can I have some handy hints for managing Xmas at someone else's please?

[sticksantaupyourchimney]

I have a 4-year-old DS and an amicable relationship with his dad though we are not a couple and were not when DS was concieved. For the first 4 years of DS' life DS and I have been to my parents for Xmas Day (I am 44 and have never not been to my parents on Xmas Day btw). This year DS dad asked very nicely if I would consider bringing DS to his parents for the day, and I fully understand that I should and that it's only fair etc. My parents are OK with it too -but I am a little uneasy as to how to cope with things ie I don;'t really know what their family traditions are or whether they will vary them to accomodate having a 4-year-old in the house.
SO, any hints any one?

make sure you get a good book for a present and take it with you. You sit and read all day while your DS's grandparents shower him with presents and entertain him

(that's what I do at the PIL's anyway )

I would speak to your ds's dad to find out the basic traditions. Then if they dont open til presents til later in the day then your ds can have that explained to him before hand if they arent going to vary that with ds being there.

ASK!
Find out what their average Christmas day is like and if there are any specific traditions. Cover, food, gifts, timings etc. so you feel a bit more prepared.
Let them know any important specifics re your ds too (food likes/dislikes, allergies, nap/bedtime)

Def have a discusion before hand about expectations etc. Perhaps start talking about traditions and what you all used to do as kids then bring it round to talking about now, rather than jumping in and saying right what do you do.

I would also be forward about asking to help with things, infact don't always ask just get on and do a few things like putting out rubbish or peeling the spuds. Unless you know they will take offense. On the other hand if you are doing too much and are exausted take the chance to sneak off and hide to get some peace for a while too.