Yeah, there's always been a disparity through most of Western culture when it comes to male and female sexuality. There's always been an unspoken assumption that sex was something that a man did to a woman - that the woman 'received' the sex in an almost passive manner. This often isn't the case, but from what I gather the great majority of 'vanilla' sex does seem to be like this. There's also been the assumpton that sex was soemthing that men wanted and women allowed men to have if they 'earned' it or had been 'good', otherwise it would be denied to them. The man have to somehow convince the women into the act - standard behaviour at nightclubs.

All of which is stupid and often not the actual case at all, but those have been the dominant stereotypical actions for the last few decades at least (and in some areas, the last few millenia).

And all of that caveman crap feeds back into perceptions on male and female nudity. It's not a complete explanation but I bet it'll account for a fair chunk of it.

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