Fish and amphibians do not have sexual intercourse. The females lay eggs outside their body, males’ sperms contact the eggs in the water. The good thing is once can produce a lot of siblings.

In mammals this process through sexual intercourse.

In male, his testicles produce hundred millions of sperm, travel to find the only one egg produced by the oval of female.

Male’s ejected penis insert into the female’s vagina. Hundred millions sperm pass this way but only one will finish the journey to the egg.

This is science.

In social science, woman is always at the losing side in sex. Pregnancy in woman, for me, I protect my self. My father told me Time magazine use pills as a cover, as the invention of fifty years, also condoms commercials appear on tv.

There is a new question, " If use pills and condoms can effectively avoid pregnancy and HIV, will people have sex the same easy as have burgers........

Father and daughter talk about sex; we talked about Second World War, history, photography, geography, poetry, why do people feel so strange on sex ? The difference between art and pornography is not very clear. Usually art dose not arouse sexual desire, pornography does......our discussion is going on.