Cats put their butt in your face as a sign of trust, affection, and friendship. This behavior is a way cats greet those they like and consider part of their social group. By presenting their backside—a vulnerable area—to a human, they demonstrate that they feel safe and comfortable. It is also a form of communication where cats share their unique scent from glands located around their rear, marking you as part of their territory or family. Additionally, cats may do this to seek attention, petting, or food, or simply because it is a normal greeting behavior among cats. Overall, it is a positive sign of a strong bond between the cat and the person.