Shewolfnm, You have several comments so -- One at a time==
It's called a quickie, a nooner, or a morner when human are unusually brief. It's reputedly popular amongst our younger citizens
JL answered your second point very well IMO natch.
Third, "What was sex like before religion.
Now I am going to "show you a facet of human nature which is all to often unappreciated
When sex was natural the population of the world was stable figured on a continental basis.
But when somebody (the writers of Genesis) wished to increase the size of their tribe they began to forbid sex except under prescribed circumstances. They also began to fiddle with penises, and call women sex organs unclean. This naturally made everybody much more interested in sex that they previously had been so consequently they would have sex more often with a resultant increase in the numbers of little Jews, Catholics or Muslims.
Please note that the societies with the most restrictive "public" sex practices are the ones that have the most children. Catholics, Muslims and Amish in todays world.
So for the "lesson"-- When government, whether secular or sectarian, wishes to make something more valuable the best course of action is to forbid, license, or disaprove of something. This will tend to raise it's perceived value to the general population which will tend to increase the supply.
The producers of marijuana, cocaine, whisky,opium, and tobacco are some current beneficiaries of restrictive governmental processes which increase the price and desireability of their products.
In the Arab and Catholic countries the churches and mosques are the beneficaries of a crop of uneducable (due to budgetary considerations) impoverished, discontented poor children which they can raise in their view of the world. (Cannon fodder-Suicide bombers-or tithers).
If you wish to experiment I will give you my observations.
Of all societies with which I have been involved the ones that thought about sex the least were nudists and naturists. The ones that thought about it the most were Catholics and Mennonites.
Go Figure
Mech