I'm not sure if I agree entirely, but I do think you're right about regarding anti-gay societal beliefs leading to the characters being unable to express attraction openly and finding some other outlet. At the very least, that's what's going on in the story, whereas in real life sometimes the original motivating factor something non-sexual that gets reexpressed in a sexual context.
There are still these contexts of people who would be 100% okay with LGBT relationships finding it weird for someone to be sucking on doll legs or where these characters are not fully seeing the people who they think they love. I don't think any of this is really a contradiction. It's more that "the series/title/ is about X" is overly reductive and that this would be a one off instead of a series if the author only had one idea to talk about.