I experience some of this with my wife, although I must say not to the level you're describing. (We're seniors, by the way.) My wife is sensitive to anything I say that she perceives as being any type of criticism at which point she becomes defensive. And, as a result, I've taught myself to stop before I speak and think about anything I might say that appears to be something she could conceivably interpret as criticism... (a technique I learned reading the books of the American Buddhist nun Pema Chodron.) I myself have a tendency to be sarcastic. And so it comes as almost second nature for me to rip off one-liners regarding almost anything that comes up. It's a bad habit I think I picked up from my father many years ago.

I also intentionally look for opportunities to agree with my spouse. There is a sales trainer by the name of Tom Hopkins (he's on the web) who teaches professional sales techniques. And one of the techniques he teaches is to look for opportunities to agree with whatever your customer might say. "They say it, you nail it down" is the phrase he uses (or at least used to years ago.) So, for example, if my wife were to say: "I really like that color combination" I could follow up with: "Yes, aren't those pretty colors!" (She said it... I nailed it down.) There's a lot one can do simply with speech patterns that will improve relationship interactions. It's simply a matter of learning the techniques and applying them.

And then lastly, if my wife says something I disagree with, before I say anything, I stop and ask myself if the subject matter is important enough that I need to express a contrary opinion. (Often when I stop and think about it... it really isn't.) If it is... I will say what I think. But if, in the whole scheme of things, it doesn't really matter, then I just keep my opinion to myself. Am I always successful? No... not by a long shot. It's an ongoing process. But it helps.

P.S. I also typically will not ask my wife not to do things (such as not put a coffee cup in the sink.) If I see she has not done something I simply take care of it myself and let it go. After all, in most cases, it's just my opinion (or perhaps preference) that the way I prefer to see it done is the correct way and the way she did it was not.