After you get a cupping sesh, it's a good idea to avoid showering for a few hours. The reason is, your skin's been through some stuff during the treatment, like being pulled and stretched, and the pores are a bit more open than usual. If you hop into a hot shower right after, it might irritate your skin or cause the marks to take longer to heal. Also, your body's still doing its thing to get rid of toxins that the cupping helped move around. Giving it a little time before getting wet just helps the process along and keeps your skin happy.