I would like to know why a lot of men like to see a women turn her self on in front of a man?

Men get turned on seeing anything that they are not supposed to see. In olden times when women were covered from head to toe, they’d get turned on by seeing a woman’s ankle. If a woman’s skirt rides up showing parts of her thigh that would normally be covered, that will turn a man on more than seeing that same thigh in a pair of shorts when the leg is bared on purpose. Watching a woman turn herself on is something that is normally not seen and so many men enjoy seeing that. 

Men’s voyeuristic nature is why it’s good to keep a little mystery in a relationship. If a woman is always walking around naked in front of her lover, then her naked body will lose some of its allure, similar to the way that men at a nudist camp stop getting erections from seeing naked women. But you’re not supposed to get turned on at a nudist camp, while a woman does want to be able to turn her man on with some regularity. So it’s okay to let him look at some very private activity from time to time, but also be careful to maintain some privacy so that there will always be a curtain for him to want to peer behind.