Normally, The man will stay in his wife's house in 3 years or 7, 8 years depending on a covenant between the two families. The bride's family will choose a nice day to hold the wedding ceremony and pick up the groom after the engagement ceremony.

A family in Thai Khao Hamlet, Yen Lam Commune, Ham Yen District took the groom to his wife's house to their house.

The Dao people believe that the live-in son-in-law custom for the purpose of attach the relationship between the man and his wife's family. The son-in-law has the same responsibilities as the son of his wife's family such as taking taking over the housework and inherits their property. After their covenant expires, the groom will pay full wedding presents to his wife's family and take his wife and children to return to his parents' house.

In addition, the Dao people still possess another form of this custom, including living with in-laws for the rest of his life. It happens when the bride's parents give birth to a single child or the man is too poor and orphans.  Therefore, those who want to live in his wife's house forever must not be granted "Cap Sac" ritual and have to change his surname to his wife's.

This is a custom with profound human value because it helps the families maintain and develop stably though the generations as well as gradually eliminating male chauvinism.