Cultural norms play a part as well as biology. In many cases girls are brought up to be "nice" girls. Rampant sexuality is still considered a virtue to many in this world. Being a "stud" is cool. Being a "****" or even an overtly promiscuous girl is not. Not very fair to girls or even to guys.
Humm just bean to Bangkok and What I have seen real live sex shows in food shop people pay huge money and take dinner while watch this , and I believe this is real bad with any lady