How do you let the person know what you are doing is for her own good? Because all she talks about when you are alone is how her partner would never seem to understand her need? And how great the pain would be if and when the partner finds out about the affair? There is no justification at all of the affair because the partner has given all that she has and more. How do you keep the strength to be silent and intentionally hurt her knowing it's the factor for the affair to turn cold?