Hetero-normative culture is the dominant force in shaping our gender identity and social relationships. There is no question homosexuals are second class citizens legally and socially, and that other self-identifications or sexuality is either taboo or ignored (i.e. bisexuality, trans-sexuality, pansexuality, etc.). The methodology of hetero-normativity comes from idea that marriage is another form of slavery, men owning women as property to fulfill the roles of baby making machines/domestic laborers and its enforcement through outcasting any person who can't/won't perform these roles - socially, economically, and/or politically. We are force fed these roles early on, which is the main argument for pro-LGBT activists, feminists mainstream and otherwise, polygamists, and people who practice polyamory, a norm in anarchist circles.
This is my qualm: I am not poly, nor am I supportive of hetero-normative culture, yet often enough, I am called out for being in a monogamous hetero- relationship; for falling prey to the hetero culture hierarchy. Without being defensive, or ridiculing anyone of alternative lifestyles, some people are heterosexual, even us feminist activists. Yes, biologically a woman's natural response is to reproduce, as is a man's, so some of us are straight, and even lesbians like to have fingers, toys, etc. that technically are phallic (although it is not necessary and doesn't make a lesbian bisexual). There are many feminist theorists that claim woman are by nature, bisexual. I don't agree, simply on the grounds I am not opposed to same-sex relations, I have engaged in same sex relations and I didn't care to have them (or not)...on several occasions. Although I am not bisexual, I am not heterosexual, either.
Can a person receive pleasure from someone of the same sex, enjoy it and not be bi? Yes, considering we can receive pleasure from inanimate objects and not have attraction to them, or have sex with a person you don't particularly have interest in, but get your rocks off (so to speak).
This is where I think many sexually inexperienced individuals become confused with the idea of bisexuality. Now, this is not to say that homosexuality or bisexuality is just a made up social construct (like hetero-normativity) but perhaps heterosexuality isn't merely a social construct. I do believe, especially in activist circles or anarchist circles (whom are mostly "alternative") it is common for poly or LGBT folks to be the norm and it is merely because, initially, the type of person to be involved with activism or punk rock (or whatever) are people who don't accept the status quo. They are the type of person who does't want to be fed more bullshit; sexuality is another outlet of that rebellion. This is also the reason why people who just are different than the mainstream norm are attracted to activism or other alternative lifestyles.
Experimenting is and SHOULD be promoted (bi or poly experimentation), but I think many just label themselves bisexual only because they've kissed someone of the same sex, or hasn't and just wants to be recognized as someone who doesn't support the hetero culture/gender system. So, to some extent, the bisexual club has racked up a significant amount of people who just don't consider same-sex relations taboo who actually act out hetero lifestyles. I also think, in some cases, the idea that it's taboo or wrong to be bi or homosexual or to be poly is the main reason why these lifestyles fulfill people sexually, which is the main reason why people develop fetishes. For example, a straight man having a woman screw them up the butt with a dildo or a lesbian woman having fantasies about being gang raped by men (these are very common fetishes, actually). In real life, the man would never want to sleep with another a man or the woman may severely oppose rape. Again, I am not proposing that those born gay, trans, intersex, etc. are just bi-products (no pun intended) of the opposition of a hetero culture, but I AM saying that there are a minority of those who consciously choose a poly or bi lifestyle that are.
As for the poly lifestyle choice, which goes along with unconventional gender identifications, sexual practices and multiple consensual partnerships or relationships, I think some may enjoy this lifestyle and have legitimate reasoning but those who aren't poly aren't just by-products of hetero culture. Especially if you've considered the argument of being forced to be hetero and forced fed the idea of a single marriage long term relationship. Yes, most marriages fail, but I believe its because people don't experiment and are pressured into having one partner at a time with marriage being the end all be all. I don't agree with the eagerness and myth of "the one". I do believe, however, biologically due to the urge of creating children and having a family, people are naturally serial monogamists as seen in many primates. Some people, of course, don't have the urge to settle down, period so they do not want to be monogamous.
But, let me ask you this: if many men, especially nowadays, want multiple partners or open relationships and many woman don't, is the popularity of poly orientations perpetuated by a culture of woman geared towards pleasing men especially in anarchist circles which are usually predominantly white young men and have traditionally set the intellectual standard due to the gender hierarchy and access to information? This could be because of socially ingrained gender roles, perhaps that aren't inherent, (that woman want a family and men want to fuck around), but it may also be from mainstream gender roles of men wanting as many women as possible (to prove masculinity/prowess), therefore it is a way to coax women. I have seen some manarchists like this and mainstream men like this. I have also been around/with people who practice polyamory that aren't like this.
I also have to bring up that within the context of marriage being a contractual agreement, where the idea was initially brought up because women were slaves to men, anarcha-feminists like Emma Goldman had a political justification and a personal frustration that was right on taking many partners and breaking that taboo. Nowadays though, people having many partners (i.e. cheating) isn't taboo, it is common. People not wanting to settle down so they can continue having sex with whoever, is common too, so, maybe it's more politically relevant to be with one person and not treat women or men as tools that are simply for sexual gratification?
When it all boils down, people have the right to chose how they want to live their lives, so don't be hypocrites you open minded anarchists and feminists, let me prefer to be monogamous and not be ridiculed for my natural inclination to have one mate at a time. I do think the ideas above are worthwhile conversation topics but ultimately would be useless to prove, considering no one has been raised beyond gender roles and without social tendencies ingrained by media, parents and school. Just keep in mind, all I am saying, is if heterosexuality can be a social construct why can't other types of sexuality or polyamory be a social construct as well?