All very true! Even if there's no new structures put in place, the surrounding environment, context, and/or culture itself can effect how relationships are viewed... and I agree with the sentiment towards aliens in Sci-fi usually bringing their own unique twist on relationships.

With good vocabulary, this is probably my own fault for not having the best words to describes these things as I don't usually interact much with things focused mainly with romance. XD

I'll definitely have to look into more writing about dark/black romances! :D