The flaw in this argument is twofold: there weren’t transexuals before western modernism, but there were androgynes. It wasn’t that the people felt they were in the wrong body, just that they were not exactly on either side of the gender spectrum. In some cultures, they functioned as one or the other, with all the duties and responsibilities, while in other cultures they had double duty. So I don’t think the problem with determining maleness or femaleness comes from the existence of transexuals, but from the cultural idea of transexualism…that there is some wrongness that must be corrected rather than the person being okay, just different from the norm, and needing to “butch up” or maybe “bitch up” depending on which suits them. Add that to the postmodernist idea of “there is no authority” including not just society but Nature itself, and there is a complete removal of duty or responsibility involved with being any gender.

I’ve seen the documentaries. Nobody bothers to tell transexuals transitioning into womanhood, what it is like to be an ugly or old barren woman. It’s all “you go grrrl!” until it’s too late, and they have to learn the hard way that there was nothing wrong with their bodies, but their sense of self worth. Same with female-to-males. It’s a hard wake-up call that once they become men they have to be men. Nobody tells them what it’s like to be a beta or omega male. Hope they had an alpha dad with the self awareness to properly teach them. If not, they end up kinda screwed.

Anyway, you are correct in the sense that postmodernist (read narcissistic) culture has muddied the lines, and that there are lines that one should probably mind or else trigger natural revulsions in their partner(s). I do think the identical genitals is a good place to draw that line. I mean, so long as we’re redrawing them, and abandoning hangups that are no longer relevant, what is the big deal if it is a homosexual act? I don’t see a problem with this because I don’t see a problem with homosexuality as an orientation or as a standby. It’s how societies used to keep from having rampant single motherhood. Apes and monkeys do it, for crying out loud. Some species, the males shag each other until they are dominant enough to get a female.

One can’t have everything with every gender. Trying to be everything to everybody will make a person crazy. There has to be a point where it’s okay to say, “I’m not into that,” about whatever a person is not into. Pegging is just one example. One should also be free to say, “I’m not into guys who are not protective,” or, “I’m not into women who aren’t managing their appearance well.” If folks are really promoting freedom, then they should be cool with the freedom to be male and female and androgyne, and not some everything “ideal” that doesn’t pan out in real life.