You didn't ask that at first? I answered both your questions which were basically joint together as one question
OK, so now you are asking me on my opinion about the example you just gave. My statement in my previous post was very general, it counts for most situations.
The example you gave is tricky and there is no correct answer to everyone in that situation. What you do depends on what you think your wife would appreciate most... do you think she would appreciate the truth but feeling hurt or would she appreciate a lie but avoid the hurt? So I can't answer it, different for each relationship.
I certainly did ask the "affair" question before the other two - Post 737 to be precise.
However, I'm delighted to see that I have converted you to my viewpoint ... good man.