According to the mother of Yang Erche Namu, the Chinese judge of their version of Pop Idol, 'good sex means good skin'.
In itself, that doesn't make an awful lot of sense, but it gets weirder. Mother went on to explain that the way to avoid zits, was to have loads of sex (to which the daughter rigidly adhered).
Therefore, logically following the argument - the more you have sex, the clearer your skin (and by definition, the more people who want to have sex with you).
I suppose it does explain why there are so many spotty teenagers getting nothing but sore wrists, but surely soap would help on the complexion front - although granted it is not going to be as pleasurable as the alternative.
Funnily enough, I guess it also explains why there are so many fucking Chinese in the first place (literally).
So, the question becomes, what other fantastic reasons for having sex could there be? (apart from putting Clearasil out of business....)