Well, another very famous italian proverb. I tried a... russian translation, as possible as I could... Every gramatical correction and improvement will make me happy.

It.: "Tra moglie e marito, non mettere il dito!"
RU: "междy жены и мyжа, не клади ты свои палец".

One meaning: "Do not ever interfere within wife and husband' discussions"

Ciao.