[W]e are living in what’s becoming an intensely performative culture, with new outlets for different personas — one for home; one for work; one for Instagram, cable, etc. Open friction is no longer so easily subsumed by the almighty virtue of comity. “Everybody seems to be playing a certain role, and that should add another layer of skepticism about what’s really going on with people,” said Gil Troy, a presidential historian at McGill University who has written about political couples.