Exposure laws question.

How come a man can get arrested for simply exposing part of his penis in public, but women go on all the time, say, at the beach exposing part (or some) of their breasts? Not talking about the nipple part, but the breast part.

STores sell clothing that ensure some of the breast is exposed like it is nothing.

Women have been breaking the law. Nipple and breast are two different words for a reason.

Is it girls 14 and up that a law states must have their breasts covered?

Enforcement of said law must be half-arse or something.