Every now and then, we do see some question like this one, which revolves around trust issues in a couple, asking us to collaborate as to "unmask" the unfaithful party.
I personally believe that the users of our site should not concern themselves with this sort of questions, belief that makes my question rather similar to iBug's one.
The difference, is that questions which are unethical may very well be of use in the future, whilst those similar to the one in the first paragraph, are probably not.
What is everyone's take on the matter? Should questions whose context is trust issues be closed or ignored, or should any potential answerer decide by their own accord whether to answer or not?