If you want some tips for hiding here is some; trying to monuver it when no ones watching so that it is straight up towards your belly button, and pull your shirt down as far as it goes. Though I am only a teen, I have found that wearing jeans instead of sweatpants or shorts is a big help. And most guys would be sticking out the waist band of the jeans if there was enough room. If I get a throbbing hardon I think of unattractive things and hang out in the pool until it goes away. A penis has a tubular shape while a clitoris has a hood covering and C curvature shape, and yet still tubelike, and rides along the body. Unexpected erections are involuntary and are normal.