One of the great problems with sexual practises outside heteronormative standards is the fact that we all know that they have already been sexualised in pornography. A common theme in the Pornographic film is the 'Threesome' scene, usually FMF(bisexual females), though occasionally MFM (heterosexual males) the sexual orientation distinction being made due to the overwhelmingly male heterosexual audience in pornography.
Is it unsurprising that people in general lack respect for triad relationships when their only cultural trope is the 'porno threesome scene' ? When was the last time you saw a triad relationship that had nothing to do with sex in our culture? We see the triad through the prism of sex. Generally, three people in a romantic sense is called a 'love triangle' and is a source of conflict. It is a romantic 'vee' two people both fighting for the attention of a hinge.
Even though the threesome is a common scene in pornography, the popular media is no stranger to this trope, I have seen suggestions of a threesome in comedy, dramas and even television advertisements for men care products. The overwhelming message we get is 'this is fun if you are young, free and single however if you are mature, it is a big, threatening mistake but you can get past it, because it is only sex' the idea that three people might LOVE each other and that sex is secondary to the relationship is alien to heteronormative dyadic society.
With triads, more so than with Poly Vees (because Poly Vees already have a less sexualised cultural standard with Polygamy) it is up to the politically motivated of us in triadic relationships to at the very least, reclaim our relationships from the Pornographic sphere, bring the notion of romantic love, mutual commitment and friendship and extend it to triadic relationships. It is an extension of our Polyamorous standards anyway, if we acknowledge and put forth the notion that our polyamorous relationships in general are not about sex, why do we find it so hard to break the stronghold of 'threesome' sex from the cultural norms of general society?
When you say you have a triad the first thing people think is 'threesome sex' but when someone states that they are in a monogamous relationship, sex isn't usually the first thing they think about, they think love and romance, friendship and companionship.