slapping down mugs

[anuch123456]

In the movie Borderline from 1950,
I heard "slapping down mugs" what does that mean?

<-----Video link removed by moderator (Florentia52)----->

Thank you

 

[Florentia52]

Please explain what is going on in the scene and give us the compete sentence in which the phrase is used.

 

[Florentia52]

You need to put the required information in a post.