18 December 2008
These are not clothing skins, nor are these default nude mesh replacements, nor yet are they Maxis genetic skintone replacements. These will be found in the custom content section of the first section of your Create-a-family (CAF) or Create-a-student (CAS) in game.
The erect penis will only be visible in such times as a real-life nude state might exist for your Sim (i.e., in the shower, bath tub, or hot tub). In regard to the proportion of a teen being 94% of an adult/elder, the teen penis is 90% of the size of the adult/elder penis.