We all know how this goes. Shits himself, kicked into a trashcan when the smell of shit permeates the room, Merry Christmas.
Plot twist, the Fluffy’s been told they’re a Christmas Present but it’s actually March.
So I’m torn about which would be the funnier scenario involving a Christmas fluffy:
On the one hand, I’d prefer to fluffy to not know the concept of Christmas, even if you explain it to them. It would just be panicking and screaming for its life because for all it knows, it’s trapped in a pweety sowie boxie.
But on the other hand, I like explaining the concept of Christmas but fluffies are dumb so they don’t understand it even if explained to them. They have no concept of time outside of bwight time and dawk time, so being stuck in a box means they can’t keep track of time. All the fluffy knows is it needs to wait for something in the future called “Cwismas” and could be holding in its shit for weeks, unknown to it.
That fluff is doomed
“Fwuffy holds poopies,
But nuu can wast…
Huwweh Cwis’mus,
Huwweh fas’!!!” 
Two scenarios, both terrible both not ideal
-
He does poopies resukting in him stinking and putting off the owner from taking him, resulting in him being thrown into the alleys to fend for himself while still covered in poopies (herds will not take kindly to self made poopie fluffies)
-
the store he was purchased from from corked him beforehand in which case he might get intestinal damage slowly bleeding out from the inside, aswell making him look very sickly once the box is opened (myabe they return him but considering how cheap fluffs are the alleyway may take him regardless)
Only option to save himself is to hold in his poopies until the box is opened but… you know… hes a fluffy so thats not gonna happen. 
fwuffy nu wan a wot for cwimmus 