Why did European aristocrats at that time allow their wives to find other men as lovers?

Because before World War I, the marriages of European aristocrats were all political marriages, which made many couples exist in name only, so they allowed their wives to find love outside marriage, but this was not public. After all, this kind of thing can't be said on the table.

Before the First World War, European aristocrats intermarried, and the royal families of various countries were surprisingly close. Influenced by the political marriage of monarchies, European nobles and courts respect the tradition of intermarriage within the hierarchy, but they are very resistant to the marriage between nobles and civilians.

At that time, European nobles would not refuse political marriage. They will still respect political marriage, but privately they are eager to find their true love, so the boundaries in sexual ethics are very vague. Their marriage is judged by rank and financial resources. Men and women can combine only because they are suitable for each other, and the love between husband and wife is insignificant.

Because the traditional class concept at that time thought that marriage and love could be separated and would not be combined. The purpose of marriage is only to let the noble family lineage continue, and the way of continuation must be decent. However, their emotional needs can only be pinned on extramarital affairs.

At that time, a noble man with a decent appearance, if he had many lovers and illegitimate children, would only think that he had a little shortcoming in the eyes of the nobles at that time, and even thought that this was his rational performance and would not be trapped by love. On the contrary, if a nobleman marries a commoner because he falls in love with her, it is a big mistake and will be criticized by everyone.