I found this awesome blog article describing couple privilege. It's literally the top search result for that search phrase, and for good reason. I've been irked by people expressing opinions that derive from couple privilege for years now, but I never had a coherent name for what they're doing, let alone what's wrong with it. This is the first time that I find such a stunning, exhaustive, concise explanation of what couple privilege is, and why it isn't a good thing.
The part that speaks most loudly to me is from Part 3 onward.