EBF, you pose a very thought provoking question. Quite a dilema!
The original question was what do we consider cheating. Those are my feelings on cheating, though in the case you pose I don't know how I would handle it either.
I would hope to be able to confront my partner with the truth, but one can never know these things until they are put in that position. As you said, do I want to cause severe pain? That is something I would hope would not occur by bringing it into the open and not attempting to hide it. Again, that is something one can never know until faced with it.
Yes I would feel hurt, let down and maybe even angry for a while, but I can't believe if my spouse came to me with something of this nature I would loose my confidence in him. Being honest is more important than anything else. He already has my permission to have sex with others, so why should it be a big deal to let me know!? All I ask is that he not sneak around. Be upfront, that way I always know(and feel) I am the one he loves!
I think it could be worse if held as a secret. Who's to say, down the road sometime it wouldn't be thrown out in the heat of an arguement. Brought up when noone is thinking clearly, or willing to understand or forgive!!?? Now that could really be a quagmire!
Who knows, if ever faced with that difficult decision, I may change my mind and lie like a dog.
mrs hmr