But not aliens, animals, bicycles and picnic tables? Well, that’s disappointing.
Just because you can be attracted to all sorts of other sexual beings doesn’t mean you’re also attracted to non-sexual ones.
I know that most pan/polysexuals wouldn’t be into bestiality, either; it’s all about informed consent. (I’ve seen this issue being raised by trolls at another messageboard and at a real-life venue, so I know what the answer was).
It is rather provincial to think that male/female as 2 genders is some sort of universal theme. We may well find species on other worlds with more than 2 genders. So WRT Captain Jack of Torchwood fame, I presumed that he would have a go with any being of any species. This is definitely beyond “bi”.
You don’t get thrown in jail for being straight, and indeed you get plaudits and credit if you pick the right social circle. (I expect there are few heterosexuals among intellectual creative types - but many in redneck country.) In those circles, opposite sex pedophilia is about the point when being attracted to the opposite sex starts to cost you social status rather than making people think you’re a normal heterosexual. And it just so happens that “heterosexuals” stop there. Again, if it was merely a matter of being interested in people of the opposite sex, you’d expect people to independently draw that line in all different places…so it’s striking that heterosexuals all happen to pick the optimal point for status seeking in their social circles.
Heterosexuality is the norm, and “heteronormatism,” to whatever extent it exists, is just the majority attempting to raise the status of its own preferences. Your semi-clever attempt at a reversal fails because the situation is not symmetric. (“Surprise, whatever group happens to be the majority is acting according to the majority view!”)
Why do you assume it isn’t symmetrical? Homosexuals predominantly find the same “line” you talk about. As do bisexuals. A normal adult of any orientation is attracted to other adults. Pansexuals are presumably very like heterosexuals and homosexuals in that their attraction to other adults is innate. They simply are attracted to multiple possible interpretations of gender.
Do you believe homosexuals are faking their interest in adults of the same sex in order to fit in with other homosexuals?
Or kitchenware.
Why did it have to be you that said this? 
I am a pansexual. If I am attracted to someone it is because of who they are, not what they are-male, female, transops at any stage going in either direction, cross-dressers, none of this matters if you are a decent human being.
We are not talking about homosexuals, so please spare the canned political rhetoric and start thinking. It is striking whenever a bunch of people converge to a single point in defining their sexual interest, and even more interesting when that point happens to be optimal for status seeking in different groups. For heterosexuals, this convergence makes sense; heterosexuality is the majority state and the majority has significant influence over culture. So it’s unsurprising that the majority group bends culture so that they are in a strong position.
Pansexuality however is at the fringes of mainstream culture (though Torchwood is doing its best!). Thus you can’t explain the convergence of pansexuals on an “everything but kiddies” standard by saying that they’re influential enough to wrap culture towards their already existing preferences. Thus the conclusion is that their preferences are dictated in no small part by moving towards the status seeking optimium, which in certain circles is exactly where they describe themselves (“free-thinking but harmless”). Thus they’re unlikely to be as completely liberated and follow-your-heart as some of them portray themselves.
athelas, are you saying that people decide to be pansexuals because they watch shitty BBC shows and think it gives them “status”? Because I sincerely doubt that’s how sexual orientation works.
Some people use them interchangeably.
Some use them to refer to not fitting into labels - bisexuals cannot be contained by the artificial dichotomy of hetero/homo, whereas pansexuals cannot be contained by the artificial multichotomy of sexual labels in general. They might just be gender blind, or might be specifically inclusive of transexuals/transvestites/genderqueer/poly/open relationships or even blind to things like age etc.
Some people use the terms culturally - bisexuals come from the gay community and culture whereas pansexuals come from hippie/new age/pagan/alternative/indy communities and culture.
Yes, some people use the term in the sense of Torchwood, even though for Jack, the possibilities of love go beyond gender/age/relationship types available to us, and include other species and time periods.
There’s also the term ‘queer’ which often is used to mean “whatever, just not heterosexual”.