It’s completely normal for certain areas of the body to turn red after sexual activity. This happens because of increased blood flow and friction, which is your body’s way of responding to stimulation. Medically, this is called reactive hyperemia—when blood rushes to an area to supply oxygen and help tissue recover.
Friction, heat, and excitement all cause temporary vasodilation (widening of blood vessels), which is why skin can appear flushed or pink. This redness usually fades within minutes to an hour and is a sign of a healthy, functioning circulatory response.