Men always approach sexual activity and orgasm with a focus on the penis: whether through intercourse, fellatio or masturbation. 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 gentle caressing. An erect penis and an urgent, passionate desire to engage in intercourse is what men bring to sex. A woman alone, or with another woman, does not have this option.
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. Women evidently enjoy sensual and intimate activity, through masturbation and with another woman, without any need for vaginal penetration.
An organ such as the vagina, which is essentially a cavity, could never be a sex organ. The penis, which is a phallus, can only stimulate the entrance of the vagina. 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. A woman offers her vagina for a man to ejaculate into, regardless of her own arousal.
We have evolved a sensitivity to touch that protects our bodies from stimuli in the world around us. 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 to touch. [i] Minor surgery can be performed on the vagina without using any anaesthetic.
The interior of vagina is inert, which is logical, given it is part of the birth canal. Intercourse involves the penis and the vagina acting as reproductive conduits. The vagina is simply an organ for collecting sperm (a receptacle). At the end of intercourse, spermatazoa (from the testes) are ejaculated and travel to the uterus (via the vagina) to meet the egg (from the ovaries).
[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. (Alfred Kinsey)
Excerpt from Women’s Sexual Behaviours & Responses (ISBN 978-0956-894717)