Chinese:

多禮必詐

(Duō lǐ bì zhà)

English:

Excess mannerism entails deception.

Literally translated as “Much ceremony will fraud”, the proverb is meant to create a distrust of those that have “excess mannerism”, or are flashy and over-the-top in their presentation, because their behavior “entails” deception.  Like many other proverbs, it’s a piece of advice and a warning, in this case to avoid liars and charlatans.