Thank you for starting such a lively discussion!
I have been in this situation (well, similar, not exact, but close enough...). I have been cheated on, and been the other woman too. I have found myself making decisions that I never thought I would make because I thought I was clear on my own values when it turns out I wasnt. Or, I was just selfish to want what I wanted at the time.
It is a very subjective place, to be where Richard is. So many things come into play. We all have some sense on this forum that people are often not aware of their poly nature or poly potential until they suddenly come across that one "deal breaker" person. People who were monogamous (happily or unhappily perhaps doesnt matter) for many many years, until they werent...
To say that lying is always wrong and people should never lie, well.... Im not sure that's really possible. Do you ever call in sick when you're not? Fake a party to get out of another social invite? Do any of us lie to our parents about our polyness or our relationships? Yes? Well then....
The question then comes up as, WHO are you willing to lie to??? And why???
Dont lie to your spouse? Dont lie to your doctor? Who else do you make the choice to not lie to? And, again, why? When I give blood I dont always tell them that I had a tattoo 6 months ago. Or that I have multiple partners. Why? Because then someone who might desperately need my blood wont get it. When I know that I am tested, go to a reputable shop, am not having risky casual sex without protection. Some people would say that is a terrible thing, Im sure. However, I also know that they test the blood, just in case I didnt know I was sick. They are just lowering the risk of exposure, not eliminating it.
I also dont understand the whole "I tell my spouse the minute I think something is happening with someone else". I mean, why would I subject my spouse (who struggles a great deal with my polyness) that there is a possibility of a relationship unless I have scoped it out first?? One could argue that it is about being up front and honest up front. I see it as unnecessarily setting him up for stress, anxiety, and heartbreak when there is no reason to.
I have never cheated on my current husband. Always told him when I had met someone and thought there was potential, but always once I had explored whether this other person also had feelings for me and it was "worth" having that talk.
Being the Other Woman, in a word, sucks... Especially knowing what poly can be, having open, honest relationships where everyone is involved in decision making when needed (like getting time together, agreements about limits, etc.). When you are the Other Woman, you get none of that. You get only what your partner can offer you, when his wife isnt looking. And, you do start to feel that if he can lie to her, he can lie to you.
I think in these scenarios I would say that in #1 I would say dont tell, and move on. Telling probably just hurts her feelings and sets up a trust issue for the rest of the marriage. If he is committed to no more cheating then he can live with his own knowledge of what he was capable of. Not everyone will just think "Whew, I got away with it!"
In #2, I think they should have confessed, together to her. If their intention was to stay together, then they could approach it as, this happened for us, and it was unexpected, and we want you to know and have a choice. I agree that not telling her seems like manipulation, getting her to stay when she doesnt know what she is staying in. Yes he runs the risk of losing Barbara, but he ran that risk when he entered the affair in the first place. Did he decide he was keeping Madison in his life, regardless of the outcome with Barbara? If so, then she was a deal breaker and he eventually will need to let the chips fall where they may...
One thing to think about: Sometimes people are NOT in relationships that are safe, and NOT able to just get out gracefully. People dont always have the "luxury" of being able to be up front and honest, because their personal safety can be at stake. I dont think this is the case in Richards theoretical scenario, but I wanted to say it anyway.
Willow