Not meant as an insult. You are just unaware of how other cultures work. I'm not an expert on all cultures, but I have the perspective of being from a culture outside of the U.S.. I also enjoy learning about other cultures either through print or electronic media, or television and film documentaries.

"I mean, assurance because of requirement that there should not be two Mrses in one house."
Where my family comes from, the problem is circumvented by having your legally recognized wife and having your "other wife". There a is word for the "other wife" but I don't recall what it is, but she is usually referred to as "the other". She is not a mistress, but treated more as a wife and often raises another family with her.
Each "Mrs." has her own home and both are loyal to the one husband.
In some cultures, it is not uncommon to have more than one "Mrs." in the house. There is usually a hierarchy in the home with wives ranging from "senior" to "junior".
It doesn't take long for each wife to become aware of the other. Traditionally, they never meet but may know who the other is. It is not a topic of polite conversation.

I recall that Americans were shocked when the funeral of former president of France, François Mitterrand was attended by not only his wife, but his mistress as well. Europeans weren't shocked by this.

In one interesting instance, some where in the Himalaya mountains, a small sub culture is so poor, that a young woman is married off to a group of brothers. The one I saw, the girl was about 18 with the four brothers ranging from about 20 to 10 years old. Each could sleep with the wife in turn.

In another mountain culture in Asia, the father plays little role in the raising of children. The woman sleeps with whom ever she chooses and the children are raised by the mother's extended family.

"Dowry" and "bridewealth" are traditionally interchangeable as the newer term is rarely used in conversation or literature. I've rarely heard the word used. But the older term, although may be technically incorrect when the groom's family pays, it is understood as payment by the groom's family.

An example:
The Hebrew Bible mention the practice of paying a bride price to the father of a minor girl. Exodus 22:16–17 says:
"If a man entices a virgin who isn't pledged to be married, and lies with her, he shall surely pay a dowry for her to be his wife. If her father utterly refuses to give her to him, he shall pay money according to the dowry of virgins." ~~~~ source: https://en.wikipedia.org/wiki/Bride_price#Jewish_tradition