This has nothing to do with marriage, but it belongs to nipple inversion, but it depends on the degree. Nipples can't protrude but are depressed inward, which is called nipple invagination. The degree of nipple invagination varies from person to person, and it is only flat or invaginated to different degrees, and it can protrude or squeeze out the nipple after stimulation. In severe cases, the nipple is completely trapped in the areola and cannot be pulled out. It is crater-shaped, often accompanied by secretions or odor. Even if the nipple is invaginated and squeezed out, it is generally small, often without obvious nipple neck, and it is divided. The incidence of female nipple invagination is 65,438+0% ~ 2%, usually on both sides or only on one side. The degree of nipple invagination may be different, which affects the appearance of breast. In addition, sunken nipples can accumulate dirt or grease, leading to infection or odor. More seriously, nipple invagination makes it difficult for babies to suck milk and lose their breastfeeding function. So if it's serious enough to go to the hospital for surgery,