The most fabulous homosocial love duet is "Au fond du temple saint" from Giorgio Bizet's "I pescatori di perle". Let me explain. Like many other 19th century operas and novels, "I pescatori di perle" (based on "I pescatori di Catania) involves a triangle of two males (pearl fishers of the title, Nadir -- tenor -- and Zurga -- baritone) and a female.
These triangles can be very nuanced, unstable, and/or submerged, such as in Otello, as it has been pointed out recently.
Or they can be practically the whole point of the story, as in "I pescatori di perle".
In many of these triangle stories, the triangle is really all about the two males working out their relationship with the female as a sort of foil. This theory is developed at much greater length and in more nuance by Eve Kosofsky Sedgwick in "Between Men (Gender and Culture)".
The notion that a triangle is often the story of two males is not always immediately apparent, especially to the listener or reader who a priori expects the heterosexual love story to be the centre of the piece.
But to many, many males who grew up closeted and could only express their affection and desire for another male indirectly, these stories are much more clearly "about" the male-male pair. In "I pescatori di perle", I was always certain that "Au fond du temple saint," arguably the most beautiful music in that melodramma and even arguably one of the most beautiful duets in ALL of opera, is a love duet between the Nadir and Zurga.
Sure, they seem to be singing about Leila.
But they are actually sharing a dream.
The beauty of their intertwining melodies belies the surface message and reveals their true passion for each other -- in the ear of this beholder. Zurga's self-sacrifice to save Nadir in the final scene offers irrefutabler confirmation of this theory. As to Othello, there's Iago's lines about Othello's supposed unfaithfulness with Iago's wife.
But there are other lines (and I don't have the play at hand to quote them) in which Iago mentions sleeping in a bed with Cassio, which offers a whole other set of motivations for him.
Or not, of course!