Men always approach sex and orgasm with a focus on the penis: either through intercourse, oral or manual stimulation. There is no debate over the male anatomy involved in orgasm because men are easily aroused.
Misconception #3: Because of the male experience, it is incorrectly assumed that orgasm is a vital aspect of female sexuality. Sex is portrayed as a mutual pleasure as if women have sex to enjoy orgasm. Women often engage in sexual activity (both alone and with a lover) without orgasm.
Imagine a lovemaking session that involves no penetrative sex. A man could kiss, caress, stroke every part of a woman’s body including stimulating her clitoris. Many women (gay or straight) enjoy sensual lovemaking that includes affectionate kissing and sensual caressing. An erect penis and an urgent desire to engage in intercourse is what men bring to sex. A woman alone or with another woman does not have this option.
Women evidently enjoy sexual activity and orgasm, through masturbation and with another woman, without any need for vaginal penetration.
Minor surgery can be performed on the vagina without using any anaesthetic. There is no sensation from stimulating the interior of the vagina.
We have evolved a sensitivity to touch that protects our bodies being damaged by the outside world. So we only have nerves that produce sensations, both pleasant and unpleasant, in anatomy that can be harmed by stimuli external to the body. The vagina has evolved from primitive egg ducts and in common with other internal organs has little sensitivity.[i]
The interior of vagina is inert, which is entirely logical given it is part of the birth canal. During intercourse the penis and the vagina act as reproductive conduits. The vagina is simply an organ for collecting sperm (a receptacle). Ejaculation during intercourse enables the sperm (from the testes) to travel up into the uterus to meet the egg (from the ovaries).
An organ such as the vagina, which is essentially a cavity, could never be a sex organ. Even the proposal that there is a super-sensitive spot somewhere within the vagina cannot change the fact that orgasm is not achieved by someone else jabbing or poking at a piece of our anatomy.
Sometimes it is suggested that a woman stimulates herself once the man has come. This illustrates the inherent contradiction between the stimulation provided by a male lover and that needed for a woman to orgasm.
[i] Unlike its vestibule, the vagina is derived embryologically from the primitive egg ducts which, like nearly all other internal body structures, are poorly supplied with end organs of touch. (p579 Kinsey 1953)
Excerpt from Women’s Sexual Behaviours & Responses (ISBN 978-0956-894717)