Lip tattoo cohabitation lips will not turn black, its relationship with cohabitation is not very big, appear black, to consider the possibility of kissing and lack of oxygen in the process of sexual relations is relatively large. In just tattooed lips are not completely healed, premature contact with the lips can easily lead to loss of color, decolorization, serious will cause redness, inflammation and infection. In the process of sexual relations, the need to consume a certain amount of physical energy, this time the need for oxygen increases, anemia is serious, hemoglobin oxygen carrying insufficient, hypoxia, will cause the lips to become black, for the normal changes, sexual relations have no effect. Usually pay attention to strengthen the nutrition, eat more food containing iron, it is recommended to go to the regular hospital, to the cosmetic department tattoo lips.