I wouldn't say upper classes did or do as they liked. Especially in medieval and early modern society where they made exceptions but social pressure to live up to expectations was very high.
The resources might have some post-columbian bias upon discovery, but the old Mayans seem to have been more gay friendly than modern Sweden by having a god of homosexuality like the Macedons. Neither were exposed to King Jacob's bible edition where most of the hatred started. https://en.m.wikipedia.org/wiki/Chin_(deity)
John Ashdown-Hill writing about Edward IV points out that political and social factors of status, practicality, propriety and masculinity were involved in which cases of homosexuality were targeted for some kind of backlash and which were more likely to be de-facto tolerated. So having the characters marry equals, and probably avoid anal sex, would reduce some of the stigma which makes it more believable that such a society could tolerate it officially. Anal sex I would really highlight is important because it's the part that solidifies its classification as a relationship of sodomy and if the recipient is subversively the higher ranked one, such as is accused with Edward II and Piers Gaveston, then that creates the most problems. But tbh, if you are writing a fictionalised version it really does come down eventually to just doing what you want. Having recognised same-sex marriages is already a change so as long as you don't go overboard, or otherwise make it feel justified and appropriate, then who's to say it's wrong?
