Have you already had your work Christmas party? If so, did you enjoy yourself?
Have a look at the following expressions for having fun:
to have a ball (to enjoy yourself immensely)
A: How was the party last night?
B: Absolutely brilliant! We had a ball!
to have the time of your life (to enjoy yourself very much)
We spent 4 weeks in Australia and had the time of our lives!
to have a whale of a time (to enjoy yourself a lot)
A: Did you go to Tom’s birthday party on Saturday?
B: Yeah, we had a whale of a time!
So, I hope you had a ball at your Christmas party, and that you have a whale of a time with your family and friends over the Christmas holidays!
All the best and have a great start to 2016!
Derek