A thought:
Maybe the dwarves themselves shouldn't know whether they're gay or not...
Do any of you read the Discworld novels by Terry Pratchett?
I just now remembered that there's a line in one of the books to the effect that the majority of dwarven courtship is concerned with trying to figure out what gender the other dwarf in the relationship is.
Yes, it appears that a lot of us do. (In fact, I happened to come to DF by way of a recommendation on the Discworld MUD.)
Discworld Dwarfs are a little different from DF ones, in that they are all traditionally male by reference. Actually, "He" and "Him" is a gender-naming convention in non-Dwarf tongues, there's no "implication of maleness" in their own tongue... For a non-dwarf to consider using (in their non-Dwarf speech) the terms "she", "her", etc, might be considered similar to someone using "it", etc, about a person of definite gender, or (by some) the singular form of "they" to short-cut "he/she" or "(s)he", and similar constructions. It at the very least annoys the traditionalists.
By conventional outwards appearance, they are also all the same (which happens to conform with maleness), with their dress being (to humans) Masculine, and all biologically growing beards. Some of the "gender revolution" reformers have started to experiment with variations on human female clothing (stiletto mining boots, and plaited beards, and indeed young Dwarfs of probable female gender have been openly enrolled in the Quirm School For Young Ladies, or whatever it's called again, adopting the school dress conventions) although I'm fairly sure that at the same time as not all gender-female dwarfs are adopting a gender-female dress-code, it's hinted that not all gender-female dressers are
actually gender-female... A kind of transexuality that really isn't much different (and probably can't be properly differentiated) from the new '
Cis-sexual' trend of the others...
Other than the beard, though, it seems clear that males and females know what
they are... Though it's probably on the same level of knowing whether one is right-handed or left-handed. And, like sinister people of the recent yesteryears would generally be socially moulded into exhibiting standard dexter-like qualities. (Only, I imagine, without the side-effects such as stuttering...)
Knowing what gender oneself is, one has a number of approaches to relationships. Having an inclination towards partner-gender, and try to find out who matches that is probably an awkward way of doing it, and besides goes against the effectively genderless approach. Instead, getting to know one's mine-mates, finding someone you are emotionally compatible with and then working with what you've got[1] is probably the way it's done. This obviously leads to male-male and female-female matches, but that doesn't matter to Discworld Dwarf society. The only real sign of an outward sign of combi-sexual relationships is a child being produced, and then I think that's it's essentially not of interest "who is the woman" in the coupling (to paraphrase the question used by bigots and heterosexual innocents newly enlightened as to the practices). The "maiden aunt" pairings and the "confirmed bachelor" ones merge with the childless male/female ones. And who knows which couples are parents to adopted children (e.g. Carrot, although I think it's said that his "mother" is actually a viable mother) or of a "parent-and-parent's-partner" type of family
In Dwarf culture what matters is the smooth running of the mine, and with longevity in the race there's not so much need for the kind of population explosion that purely hetero-couples would produce.
A distinct exception to all of the above, and the stereotypes, is Cassanundra. If a true Dwarf by nature, he is almost certainly no longer a True Dwarf in the "halal"/"kosher" sense, having shaved his beard, in the fashion of a foppish courtier and travelled in the world of man (although mostly in the boudouirs of Ladies, he would definitely have you believe, from which he seems to probably try to progress into their underthings, with an unknown but assumed level of success, with the help of his stepladders).
Anyway, that's how I see it. There's probably some minor details different from the likes of that given in the Discworld Companions, assorted other official and/or fan-written interpretations and of course the writings of PTerry himself...
[1] edit: It's at this point where the "trying to figure out what the gender of the other dwarf is" part happens, and probably more to prepare themselves for what kind of relationship they're leading themselves into than into making sure "they get what they want" out of it... After all, emotionally and psychologically compatible is emotionally and psychologically compatible... Or so I envisage it. I know there are other interpretations of the way the phrase is used[2].
[2] A phrase that first occurs very early in the Discworld Canon, not too long after the start of the series when the Discworld was not so Well Formed as a literary construct, which may also explain why Carrot does refer to "Mum and Dad" as opposed to some form of "Parent and parent", in the first place... Or his tradition-flexible parents, already non-isolationist to the world of non-Dwarf peoples and inclined to raise a human child (yet one that all but the ultra-traditionalists still consider to be a True Dwarf) are open to the kind of sexuality dimorphism exhibited outside Dwarf-kind. Anyway, YGTI.