Dunno what to tell yeh mate, it’s about as oldif not older than Furry culture. Weeki Watchee springs started a whole thing with their Mermaid shows and the subculture basically took off from like the early 60’s… And was probably about as horny as a lot of other subcultures that started around the same time.
As someone who is 15 years into the situation OP described - yes it’s somewhat of an oversimplication of how it all works… but broadstokewise it’s on the money with the right partner and mindset. Whether your marriage works this way or not comes down to how fungible you both believe your partner to ultimately be and how much you dedicate to being each other’s joy.
Thinking being pessimistic in the face of romance is just “reality” means your chances of experiencing that kind of romance become mighty slim. Optimism and trust are nessisary components to making it happen but are sadly also attractive to abusers. End of the day I wish OP the very best of luck because coming home to your partner excited to see them every day for years on end really is worth the attempt.