Als de kat van huis is… [Spreekwoord]

proverb02

Als de kat van huis is, dansen de muizen op tafel

Literal Translation: “When the cat is away from home, the mice dance on the table”
Meaning: “Grabbing the opportunity when nobody watches”.
Better English: “While the cat’s away, the mice will play”.

Maak dat de kat wijs

If you do not believe what a speaker says, you might use one of the following expressions, building from polite to more informal/strong:

Dat lijkt me sterk

That doesn’t seem to be true

Dat geloof je toch zeker zelf niet?

You don’t believe this yourself, do you?

Maak dat de kat wijs!

Tell that to the Marines (‘You’d better convince the cat’)