What does slag gate mean?

The scumbag door should be an inverted marriage, which means that after a man and a woman get married, the man goes to the woman's family to get married and settle down.

This kind of marriage is mostly in the woman's family where there are no brothers or brothers. , to recruit a son-in-law to carry on the family line.

There was a bad habit in the old society. When a man got married and settled in a woman's family, he had to take the woman's surname. This was called "cutting in the door upside down",

"The boy is incapable of changing his surname and name" and so on.

After the founding of the People's Republic of China, in order to change the concept of men being superior to women or women being inferior to men, equality between men and women and monogamy were vigorously promoted. The traditional "door-stepping" was greatly weakened, and it was just the place of residence.