The Vanderbilt's problem is a somewhat unusual one, though it is not the first such case I had heard of. They have to choose between two possible alternatives in coming to grips with the problem.
First, Mr. Vanderbilt could begin to undergo a period of psychoanalysis. The analyst would have to probe deeply into his mind and discover the original conflict which went unresolved and is now creating Mr. Vanderbilt's strange lust. This is a process which would take perhaps seven years. It would be quite costly, and the realization of the source of his problem would not guarantee Mr. Vanderbilt his freedom from the desire to witness his spouse engage in anal intercourse.
The second alternative would be to continue on present course. The Vanderbilts are mature adults, with a considerable degree of insight into their problem. If they can maintain a friendship with the Thompsons, who are equally understanding of the situation, they might very well be able to live perfectly harmonious sexual lives. It would be far different from the norm, but that is irrelevant as long as it is satisfying to the four adults.
The latter alternative appears to be the best for the Vanderbilts at this time, and they have already begun to enjoy their sexual lives together, with the assurance that their behavior is acceptable.