Hello and welcome. That concept is non-sense and absurd. These are solitary animals. They PREFER to be all alone. One could argue that its cruel to force them to live together. I would agree in some situations and disagree in other.Hello again, I have read many places that it's cruel only to have one. But that's not true I can hear.
I'm from Denmark, sorry my English not is perfect
In practice, groups of juveniles of most species get along fine. With adults it is usually necessary for most species to have only one adult male per enclosure with two or more females. Exceptions abound, but this is generally the case. I would agree that its not okay to keep them as a pair for any species or age.