Hello guys..i need your help pls cause i’m stucked for months 🙁

There was a comedy movie and i remember the main actor was famous..

In the plot i remember one scene..sorry for my english..

There were employers of some company (with their wives i think) on a train and were travelling somewhere the boss has said..i dont remember if the boss was on the train..i think for the weekend..and they were waiting for boss to announce who would get promoted? ..

The funny scene i remember was a (blonde ?) chick..if i remember right was the boss’s wife..they were sitting at the restaurant of the train..then in front of main actor she took a piece of butter from the table and she put it under her blouse on her breast (she wasnt wearing a bra) and when she put it off the butter had in the center the shape of her big nipple..and the main actor left speechless..