Maybe it seems like wishful thinking to you, I see it more like that you, Mike, are thinking in terms of what a more ethical guy would think and do given that situation, and that they'd think and do as you think you'd so think and do in that situation.
Now, it could be that a WAS lies to the OP and doesn't tell them they're married, and such an OP, upon discovery otherwise, might very well be a more ethical person who never would've gotten involved had they known the true circumstances and wish to bow out of the picture. But even then, that's if emotions haven't gotten too strong a hold of them so as to lead them; there have been clergy who have had affairs, you know, and others who at one time would've never thought they'd do such a thing ever.