Note: I’m going to use more than one term to describe similar things. All less usual terms regarding gender and sexual orientation are linked to explanations of their meanings.
Bisexuality immediately doubles your chances for a date on Saturday night.
This was perhaps intended to be tongue-in-cheek but sentiments along those lines are often expressed in earnest, resentment, envy, or some combination of the preceding feelings. Essentially, the claim is that people who can be attracted to more than one gender identity must be multiplying their number of potential non-platonic options.
On its face, it seems to make simple mathematical sense. Let’s pretend that I’m a woman who is only interested in men. As a straight woman, I’m limiting myself to less than half the population, i.e. excluding all non-male people. Now, let’s say that I’m bisexual, pansexual, or otherwise into not only men. The more gender identities I’m potentially attracted to, the more people are options for me, right?
It ain’t necessarily so. Love (or lust or attraction) is not a straightforward lottery system. If you’re calculating your perception of someone else’s odds, you may not be seeing all of the factors at play.
If by “options,” you mean “people that person could be attracted to,” perhaps such is the case. However, the word “options” (as well as what Woody Allen is saying) quite strongly implies that the attraction is reciprocated. Someone is only an “option” for you if they’re into you, too. This complicates matters significantly. Just because a person could potentially be attracted to more members of the human population doesn’t mean that more members of the human population are attracted to them in return. It could mean that for some people, perhaps, but such is not necessarily the case. Monosexuals, even the queerer ones, aren’t always the biggest fan of nonmonosexuals.
Further limits may arise when considering the preferences that nonmonosexuals may have. Specifically, I will venture to guess that many people who identify as pansexual (as opposed to those who do as bisexual) have political reasons to limit their dating pool. Pansexual people both acknowledge and could potentially be attracted to people who aren’t cis men or cis women. This could mean that they would be far less likely to accept intolerance of trans* and non-male/female-identified people in their partners. Basically, my conjecture is that fewer pansexual women will brook bigoted boyfriends and vice versa.
To be fair, I definitely know of pansexuals who experienced an increase in options when going from identifying as straight to identifying as pansexual. Such is not universal, however. To cite my personal experience, I had far more options (albeit only male ones) available to me when I was a straight-identified woman than after I started identifying as bisexual. While the culturally-assumed straight male fetish for female-on-female “action” might have just caused a collective eye-roll, consider the important difference between reality and fantasy. Plenty of men who enjoyed porn featuring only women expressed insecurity about my leaving them for another woman, believed that homosexuality is generally wrong, or otherwise felt uncomfortable with dating a bisexual woman. Then there were the fetishists: men who had a pre-made fantasy about femme women performing sex acts on each other for his viewing pleasure rather than for their own pleasure (i.e. the ones scared off by my talk of butch lesbians).
As for women, many of the lesbians I met were wary of me, fearing that I might leave them for a man — that I was just “experimenting.” Validation for their fears existed with some of the bisexual women I met, the ones who were only interested in sexual play with other women, not necessarily anything beyond a casual encounter (and sometimes one that had to involve her male partner, no exceptions).
Later, when I started identifying as pansexual, my pool shrunk even further to preclude the option of people who think “pansexual” is a silly and pretentious orientation (you wouldn’t believe how many people there are who think that way) and those whose transphobia was revealed when they realized that some of the people to whom I am attracted are trans*. Good riddance, certainly, but still a limit placed upon number of options. My lived experiences as a radical queer, atheist, and feminist woman of color further constrict my options: I am wholly uninterested in anyone who opposes or questions the rights of my friends and I to exist and live as we do.
Orientation aside, one’s attractiveness (or perceived attractiveness) plays a significant role in the number of one’s options. A very attractive straight person would likely have more options available to them than a less-attractive pansexual person.
Individual experiences notwithstanding, saying that pansexuality or any other nonmonosexual orientation by definition and by default means more options available is a false generalization The number of available options really depends on the person in question.