When a clandestine couple kisses, it is much more likely that sex will immediately follow. This is because there is much more risk. Once you have kissed secretly, it is very difficult not to have sex. It would be impolite not to have sex. You have to show that you are serious about each other.
I'm also interested in the modern suggestion that you can have a combination of love and sex in a marriage - which no previous society has ever believed.
It is said that when manners are licentious, a revolution is always near: the virtue of woman being the main girth and bandage ofsociety; because a man will not lay up an estate for children any longer than whilst he believes them to be his own.