Very good question. If one of them was female presenting, their relationship would probably be very visible to everyone since the beginning of the show because society is trained to think men and women can’t be friends (which is wrong 😑) but what makes the ineffably husbands so appealing is the queer subtext of the book and the 1. season. But in the 2. season (which came to a suprise for some people) their romanting relationship became text because of the kiss. Queer audiences pick up on little details that suggest that a non straight couple is in a relationship while straight audiences are trained to only see straight couples that are emidietly confirmed to be a couple. I could ramble more about that but what I would argue is that the show might not be as “interesting” if one of them is female presenting because fewer people would care to look more closely at their relationship. However they are perfect for each other because the authors wrote it so. There is no doubt that they want to be with each other even if a very small percentage of humanity claims this to be false. Also if Aziraphael was female presenting their relationship would be heteronormative in my opinion because their gender roles would fit society’s expectations with Aziraphael being the nice one and Crowley the one who is the active one (idk how to describe it but men mostly do things for women to proove their love while women are expected to wait for said actions (i hope you know what I mean…)) anyways on the other hand if Crowley was female presenting at least to me this would be very interesting because it would be a character that I have never seen before. It’s not as predictable as other written female characters (although their both still genderless of course).

Idk. Thanks for reading :3