Earlier quoted context omitted.
>Yes, it absolutely is always unethical. [...] Nothing is as black and white as you are claiming it to be. The irony thickens. Let me rephrase you: "Who are you, or anyone else, to evaluate 'abuse' in a relationship..." -- the answer is "anyone who knows how to count". While there are exceptions to every rule, the majority of cases fall into rather ordinary examples. Not everyone is special. Of course, indiscriminate…
Nobody asked you to intervene in their marriage, investigate their spouse, or enforce any laws -- adultery isn't even a crime in many places. You do not get to impose your morals on others. A stranger cheating on another stranger has nothing to do with you.
Odds are that people don't want their spouse cheating on them.
Someone stealing from someone else doesn't have an affect on me either, but I would operate under the default assumptions that 1) they want their things 2) they would want to be notified if someone wanted to steal their things 3) they would want to be notified if someone actually stole their things
And guess what? People acting in this way has the prosocial implication of teaching people that stealing is bad, and gives me the assurance that if someone is trying to steal from me that people will let me know!