This strikes me as evidence that such entertainments were probably most prevalent among the gay community of the time; one of those badges of 'in'-ness, like green carnations or Beardsley's spectacularly emphatic æestheticism: so that this would be one of Wilde's well-documented coded signals to his circle as to where he {& hence Dorian} were coming from: which, as he knew very well, & rediscovered in most emphatic terms 5 years later, were as far it was safe or expedient to venture in the 1890s.