"The real point," Sam said quietly, "is that we two are now partners, much more than we ever were even at the best period in our outside marriage - and we got that way through the training, culminating in sharing and growing closer with others who had the same training.  We all wind up in twosome partnerships inside the larger group - usually, but not necessarily, with our own spouses-of-record.  Sometimes not... and if not, the readjustment takes place with no heartache and a warmer, closer, better relationship between the soidisant 'divorced' couple than ever, both in bed and out.  No loss and all gain.  Shucks, this pairing as partners needn't even be between man and woman.  Dawn and Jill for example - they work together like an acrobatic team."