the most thrilling relationships for a man are another man's wife, a maidservant, a mistress, a prostitute, and finally his own wife
A classical proverb listing the supposed ranking of romantic or sexual relationships by excitement, from most to least thrilling. Rare and archaic in modern usage; encountered mainly in historical or literary contexts.
いっとうにひさんしょうしぎごさい is an old vulgar expression ranking types of relationships with women.
A fixed proverbial expression of uncertain origin, likely from Edo-period popular culture. The exact derivation is uncertain.