Ah William, where've you been? The party's already begun.
5 seconds sound clip from the Trading places (1983) movie soundboard.
You can hear this line at 01:13:14 in the Blu-ray version of the movie.
Quote context
[...]
- You have work to do and so do I.
- Nobody works on Christmas Eve.
- I'm gonna go shopping and then I'm gonna come back and make you a nice quiet dinner.
- Christmas, huh? I'll give him a Christmas present he'll never forget.
- Ah William, where've you been? The party's already begun.
- I have some work to finish in my office.
- It's Christmas Eve and William wants to keep working.
- I'll think of you in Stockholm, when I accept the Nobel Prize.
- The wager has two parts as I recall - something about a second party turning to crime.
- Didn't you say you had some work to do, Valentine?
[...]