Lost love couples who reunite while being married to other partners have referred to themselves as "happily reunited." But are these people actually reunited if they are in secret affairs and they have unsuspecting spouses, too? And how can they feel such happiness at the expense of others? Don't they feel guilty? I will leave the morality to each reader and only write about what I have found.
I found in my worldwide research, with thousands of couples, that some people feel remorse over their lost love affairs and some don't. For couples who were broken apart years ago by situations (sometimes tragic) outside of the control of their initial romances - it can feel to them like the person who preceded the marriage is not an affair, but the person they should have been with all along - a partner restored to them, an entitlement, not an affair partner. Many couples have written to me and used the phrase "grandfather clause." They want to right the wrong from years ago, and if that means others will get hurt along the way, so be it.
People feel what they feel. They can't will themselves to feel remorse if they just don't feel it.
And, they can feel happiness and joy within the lost love reunion, with the lost love partner restored to their lives, and at the same time have feelings of guilt (and often love) for the spouses.