Hi Tigger40,
If I understand correctly, your question was, Has anyone here been in a cheating situation (such as a man with a lover his wife doesn't know about), and if so, what were the results?
I have heard more than a few people say that their polyamorous life started out as a cheating situation (an affair). I even know of one situation where the cheated-on spouse never found out about the cheating, and yet the situation eventually morphed into a polyamorous arrangement which that spouse did agree to -- though he agreed without finding out about the cheating. So does that count as bonafide consent? I don't know; maybe not.
Most of the cases I heard of ended with the affair being discovered by the cheated-on spouse, and there was a whole lot of pain and heartache before anything got resolved. Sometimes the person who was the secret lover had to be ejected from the picture before anything could get resolved, even if the original couple did eventually decide to try (open/honest) polyamory. So the secret lover did not end up being able to be a part of that happy ending.
Cheating is, arguably and/or admittedly, exciting in some ways while it lasts, but it's reeeally dangerous behavior to engage in. Part of the counsel I usually give people who are cheating is, if you really feel you must cheat, at least have an exit strategy to end the dishonest dynamic as soon as possible. Otherwise you're tempting fate to hit everyone over the head with a big ol' hammer. Secrets have a way of getting found out.
Okay, so now you know more about what the practical outcomes and likelihoods are. Now, what about the moral/ethical considerations? Even if you knew you could cheat without getting caught ... even if you knew you could have a great time without paying for it ... wouldn't you still want to refrain from doing it because of the wrongness of the dishonesty?
Yes, as has been mentioned in this thread, many polyamorists (me included) lie by omission to most of their traditional friends/family. So I guess you could argue that polyamorists are hypocrites to be preaching about honesty. But I believe there's a big difference between what you tell your extended family and what you tell your spouse. Your spouse has a special right to know stuff that the rest of the family perhaps doesn't.
I have done many wrong things in my day, and thus have no authority to act like I'm standing on higher ground. But the ethical code I currently try to adhere to forbids me to condone being the secret lover of someone whose spouse doesn't know. It forbids me not because of the practical risks (which are many), but because of the moral implications. Cheating is just too darn dishonest for me to condone it.
Now what if there was a cheating situation that morphed into a poly arrangement, and somehow everyone managed to not get hurt in the process? I guess you could argue that if no one gets hurt, then no obvious moral code has been violated. I don't know the answer to that riddle. I do know that cheating tends to put multiple people at great risk of getting hurt, and in that sense it's immoral.
It would be like letting a couple of toddlers play with a loaded gun. If no one got shot, well, then, maybe no moral laws were violated. But the fact that people were inserted into a very risky situation makes it irresponsible at best.
But strictly in answer to your question: Yes I do know of a few secret affairs that morphed into poly configurations -- not painlessly though. I think if those people had it to do over, they'd do it differently.
Hope that helps.
Sincerely,
Kevin T.