In what's probably a WAY long past attempt to get back to the OP's starting topic...
If there were a gaylien romance interest, I think I'd prefer to focus more on the alien than the gay. At least if the alien is a new species, rather than a Milky Way.
In ME1-3, aliens were basically just humans with funny skinsuits. Useful for the charicature of the hour (Krogan- manly tribal savages! Rar!), but not very alien in how they viewed themselves. That helped make them relatable, I suppose, but it also made them, well, humans in funny skinsuits. For a brief moment the Geth were the only aliens worth the name, until pinnochio syndrome overtook them. And honestly, for the most part, I don't mind- charicatures or not, they got to play with themes and such that were worthwhile. Except the Asari, who were little more than lesbian space babes of 'respected' sci-fi.
But none of them really had a sense of questioning the species gap, or even the compatibility. Tali was concerned about her immune system. Liara had a 'I'm monogendered,' which was spun in some quarters as little more than a hand-wave that could appease the likes of real-world social conservatives and Fox News. But even, or especially, Garrus- the least human love interest of them all- never really dabbled into what such a relationship could have, even though there was the protein split.
What I'd like to see is an alien love interest who questions what it means to be 'male', let alone the species gap. A species where 'male' doesn't just mean 'culturally recognizable male anatomy jokes', but something else. Different, alien, unconventionally male- and then build from that, to questioning xenophilia. For the milky way, it's an established and unquestioned thing- in Andrameda, it could be new, novel, and even taboo.
If we're going to use aliens and love itnerests to explore real world social things, I'd be all up for exploring the idea of 'overchanging a social taboo' from that direction for once, rather than just going 'so... how does anal work with that?'