If women had orgasms by inserting objects (such as an erect penis) into the vagina, they would seek this type of stimulation themselves. Research has clearly identified the clitoris as the focus of female masturbation.
Orgasm is a basic response of the human body. So the female orgasm must have evolved by the same route as the male response. The ducts that form the vagina wear out in a male fetus. So, for the vagina to be a sexual organ, women would have to have developed a response capacity independent of men. There is no justification for the female orgasm as it has no role in reproduction. We only develop functionality for reproductive or survival reasons. Women are only able to have an orgasm because they have a phallus.
The hymen is a small flap of skin that covers the entrance to the vagina (in most women). When the hymen breaks there may be some bleeding and some discomfort. Before the days of tampons, women’s hymens would break the first time they had sex. This is clear evidence that women did not masturbate by inserting objects into the vagina. Even today, when women use tampons to absorb menstrual blood, they do not derive sexual pleasure from inserting tampons into the vagina.
Most people could probably accept that a man (or woman) who is a recipient of oral or anal sex is not sexually driven to participate in the activity. Only the outermost portion (entrance) of the vagina and rectum have tenderness. The mouth is the most sensitive body orifice, but men know that giving oral sex does not cause orgasm. Only the female anatomy (such as the breasts and the vagina) is attributed an imaginary sensitivity. The fact that women never challenge these myths is an indication of women’s uncertainty about their own arousal, as well as their desire to please men.
A cavity is made to contain something. In the case of the rectum, it is feces. In the case of the vagina, it is semen. Neither of these organs is erectile. It is the flow of blood to the penis that makes orgasm possible. It is the flow of blood to the clitoral organ that motivates women to masturbate.
The vagina evolved from primitive egg ducts. The vagina is part of the birth canal and (like all internal organs) has little sensitivity. We only have sensitivity in our anatomy to protect our body from external injuries. The intense climaxes that women report during labor come from physical peaks when the baby’s head breaks through the vaginal opening. This sensation can be replicated by the hand (vaginal fisting) not by the penis (regardless of size).
An anatomy like the vagina, which is essentially a cavity, could never be a sexual organ. You can always penetrate a cavity. No body opening (including the mouth, anus, and vagina) can be a sexual organ. There is no point at which additional stimulation becomes undesirable and pointless. This is the clearest anatomical evidence that the vagina could never be a sexual organ.
Intercourse involves the penis (a phallus) entering the vagina (a cavity). There is limited opportunity for the penis to stimulate the vagina in any way because it is relatively long and thin, while the vagina is like the inside of a balloon. The only possibility is that the penis hits or pushes against the walls of the vagina. This is not the right type of stimulation to cause orgasm. The stimulation needs to massage the blood flow inside the erectile organ.
The anatomical evidence of the clitoris is indisputable. Instead of abandoning the vagina as a possible source of female orgasm, the clitoris has simply been added as an additional piece of relatively minor anatomy that can help with arousal for some women. The determination to believe that the vagina must play a role in the female orgasm means that even today people assume that women have more than one sexual organ. So while men clearly have only one sexual organ, women are supposed to have two. This is clearly a meaningless concept to any rational person.
When asked about the anatomy involved in the female orgasm, women often imply that it is a specialized topic that only sexologists can comment on. This is because the sensations of intercourse are vague and diffuse. So the anatomy involved in the orgasms women think they have could be attributed to anatomy anywhere in the pelvis. More informed women simply choose the vagina or clitoris as the source of the orgasms they think they are having.
Women do not appreciate that orgasm is achieved by stimulating a specific anatomy. To a receptive woman, it is as obvious that the clitoris is the source of her orgasm as it is to a man that the penis is the source of his. The mental arousal that comes from focusing on specific erotic concepts tells us the anatomy that needs to be stimulated. Anyone who has ever been aroused can identify her sex organ.
However, there is no evidence that the vagina is the only source of arousal, or even the main source of erotic arousal in any woman. (Alfred Kinsey 1953)