Basic Types of Sexual  Behavior

2. Heterosexual Intercourse: Genital Intercourse

Coitus

Couple beginning coitus. After an ancient Greek vase painting, Staatl. Museen zu Berlin, SPK

Techniques of Coitus 7
It used to be believed that certain coital approaches were especially effective because they made it possible for a man to stimulate a woman's clitoris with his penis. By the same token, certain other approaches were considered inferior because they allowed the penis to leave the clitoris completely unstimulated. Modern sex research has shown that both assumptions are false.After all, with mounting sexual excitement the clitoris withdraws under its hood and thus becomes inaccessible to any direct stimulation. However, it is stimulated indirectly by the movements of this hood which are caused by the pushing and pulling of the attached minor lips as the penis moves back and forth inside the vagina. This indirect stimulation is almost always assured. It does not matter all that much from which direction or at what angle the penis is inserted.
However, there is one approach that many women find particularly satisfying, because it gives them almost complete control over the coital movements: straddling the man who lies passively on his back. This approach was also very popular among the ancient Greeks and Romans and was, in fact, considered "normal" by them. Today, it is often recommended by sex therapists because it seems to help both men and women to overcome sexual inadequacies (see "Sexual Dysfunctions and their Treatment")