An interesting fact that I've recently come across: a man in a long term relationship experiences a significant drop in his testosterone levels compared to before entering said relationship. Though, I assume if you start mongering, the levels rise again.
Men are by nature promiscuous, the only reason we feel guilty about it is that civilization is necessarily built upon female morality.
Japanese women pretty much know that 1 year after marriage, the sex is over. There's even a great term for the once a month bonk that the guy grudgingly gives his wife; giri manko = obligatory pussy.
A foreign guy can do very well for himself servicing frustrated wives in Japan - not that I would ever do such a thing.
