In American lingo, they would say that they have something “up their sleeve”
Whilst the Swedish and the Russians would say “they turn to the left”,
Israelis would say “they eat at the next table”
And the Japanese would say “they make themselves scarce” with “sex friends”.
With a sportive metaphor, the Irish play “offside”, whilst the English go “play on another ground”.

The French, stray from the straight and narrow to “look elsewhere”
There are some among these expressions which tend to minimise adultery…

The Indonesians provoke an “enchanted interlude”

Other expressions are more explicit !

In South Africa, a seducer is a “sprinter”, a term suggesting their sportive feats.

A Chinese man worried about satisfying his wife and his mistress at the same time is forced to “manage two boats at the same time”.
We will excuse the Taiwanese on the grounds that he is a “big turnip with a coloured heart”.

If we are not mistaken in Tel-Aviv they would say “even when attached, a mare needs to eat”.

Subtle and funny, aren’t they?!

* Expressions found by Pamela Druckerman