It's not a bad thing that you found the running water to feel good having contact with any of your body parts. Children discover there is something that feels good in that area, but they don't know what that means. It's just another part of self discovery. That is a sensitive area of the body, not just sexually, but also brings a relief when we gain more control over going to the bathroom on our own instead of just going in a diaper and also becoming more aware of keeping that area cleaned too. Children have to learn to control that area of their body and to learn how when they do go on their own to also wipe themselves and keep that area clean.