Well, there are several answers to that. Private Lives isn’t popular just because it is funny, though in the right hands it can be, very. It is a much subtler play than it was once reckoned by those critics who dismissed Coward as, in his own rueful words, a “capering lightweight with neither depths nor real understanding”.

It is about the hate that inhabits love and, at times, makes it more powerful. Moreover Elyot and Amanda, the recently divorced couple who run into each other while they are honeymooning with their second spouses, can be interpreted in several different ways. Even if one doesn’t trot out the dread word “subtext”, that is still a sign of a play richer than it seems. The protagonists are selfish, fickle, wayward, unreliable, difficult, maddeningly attractive; yet good actors can make you feel that they are more than that. They are sad, angry, maybe even doomed.

Stevenson and Lesser brought out that and received an unfair critical pasting in return. They “weren’t funny enough”. But perhaps Duncan and Rickman, two charismatic performers together for the first time since they canoodled and sneered and plotted in the RSC’s Les Liaisons Dangereuses 20 years ago, will manage to make us laugh and feel. That is the challenge. And that is the answer to those who feel they have seen Private Lives too often.