Ask them if we can drink it now. LOL

I'd say it depends on what both parties decide, the relationship between the parties, how close to Christmas and a few other variables I can't think of right now. I'd want to take it home and open it on Christmas but if they wanted me to open it in their presence, I'd surely oblige.

I say, "Thank you" "How thoughtful" or something similar and then ask, "Do you mind if I open this on Christmas Day?".      

I ask if i should open or wait.   Also depends on who may be in the office also.

I'm with Michael Jacobs After showing my appreciation, I ask if I may open it. 

This happened to me and caught me off guard. I thanked them for their thoughtfulness and they said "open it now!" Obviously they wanted to share the joy of the moment.

I only have one business associate with whom I do gifts and we usually open when we are together.

I would open it in front of them so that I could thank them right then & there.

Ask if it's okay to open now, or should I wait until Christmas?

I ask them if it's OK to open it then and there.

Hella,

It depends, and I agree with Michael Jacobs .  

I do exchange gifts with some business associates and we always open them in front of each other. I think Michael Jacobs has a good reply..nothing really set in stone.

Good Morning Hella Mitschke Rothwell.  I think it's a personal preference that depends on circumstances/choice/culture.

My first thought is to Thank them, and ask if it is 'ok' with them if I put it under our tree, to open on Christmas Day?  If they want me to open it then and there, then I would honor their request.  I think if others are not opening gifts, then it could be awkward to do so if you are in a group, but then that's just me Hella Mitschke Rothwell! 

I ask if I can open it now! But I love Candice A. Donofrio 's response!

In most cases I can read the client just by wheather he/she hangs around when they give it to me or if they say Merry Christmas and head for the door Hella Mitschke Rothwell 

Christmas day

Unless it's an unwrapped edible, I take it home and put it under the tree.

Open it now, or ask them their preference.

So Candice A. Donofrio always walks around with a cooler full of ice?

I ask them if they want me to open it now ... or should I wait until Christmas.

I always ask if I can open it then and there.  None of them has ever expected me to wait until Christmas day.

I open it there.  Waiting until Christmas never occurred to me.

Good question, I would say open at the time they give it to you.  Just my opinion.

Why don't you ask for permission to open right there and then? I am sure they want to see your expression and gratitude.

I usually ask them if I should open it or wait.  Candice A. Donofrio gave a good answer.

Depends

I never open gifts in front of giver unless they request me to do so - I've always found this to be rude - but that's just me

Put it under the tree

ditto to what Michael Jacobs said....

I ask them which they prefer and go with the flow!

I'm with Michael Jacobs on his response.

I would thank them and ask if they want me to open it now, or save it?

William Feela nailed this one!

I share my appreciation with them and then ask if they would like me to open it now or put it under my tree.  

When we exchanged, we used to open them on the spot.

Christmas day...

Much will depend upon the circumstances. I would normally open business gifts.

When that happens typically I ask, some people like to see you open a gift.

Hella Mitschke Rothwell -  I think it is a good idea to open in front of the person.

I have no rules. If they ask me to open it I do and even if I don't like it I act surprised and pleased. if under the tree I send them a thank you note.