In the original Kinsey study, itself women were more sexually open and diverse than men.
Since then several studies have shown that women are sexually more fluid than men.
Women have shown the ability to be sexually aroused by a wider variety of stimuli. For example, while heterosexual men cringe at gay po*n. Straight women and lesbians have shown enjoyment and arousal to heterosexual po*n, lesbian po*n as well as gay po*n (a subject tackled in Kids are alright).
Amidst teenagers and young adults writing fan fiction straight men write strictly about heterosexual couplings, gay men write more exclusively about gay couplings, while teenage girls ship and write without any gender or sexual orientation limits. Visit any fan fiction or erotica site and you will see this evident.
When they discovered that humans secrete pheromones too and that infants may identify parents by their scent, they also uncovered sex pheromones. Women showed a tendency to be attracted to all pheromones while men reacted only to certain groups.
The menstrual cycle also seems to impact how women view sex. During some phases of the cycle, women hold onto their traditional relationship, orientation, and sexual patterns. During other phases, women express higher libido, willingness to try anything, and a feeling of having no sexual orientation. Male libido does not seem to be impacted this way by hormones. Their sex drive may go up or down depending on testosterone but their sexual orientations and tastes remain static.
Sociologically female friendships are very different from male friendships. Women will display platonic affection in very physical manners, appreciate their friend's beauty or sexiness, and express willingness to choose lifelong bonds with friends over romantic relationships. Men have a lot more physical boundaries, and actually, experience jealousy or insecurity towards their more attractive friends, and don't think friendship bonds can substitute for romance. (Of course, there are always exceptions).
Women of all sexual orientations show openness to the notion that a person of any gender could make a good lifelong partner. Men tend to limit these notions to their gender.
So there are a lot of physiological and sociological factors that make women a lot more fluid than men. With changed socialization, men are opening up and expressing more fluidity. But there are physiological limitations that will prevent them from being as fluid as women.
A book on complex sexuality of women. It cites a lot of scientific studies and anecdotal evidence. https://www.amazon.com/Sexual-Fluidity-Understanding-Womens-Desire/dp/0674032268
Kyunki Saas Bhi Kabhi Bahu Thi 2
Geet - Hui Sabse Parayee
5