Stimulation of the genitals using the mouth.
The Beard’s climactic scene, an oral sex act, is not as startling or fresh as McClure apparently thinks. It is a continuation of the second act curtain of Albees Tiny Alice, in which Irene Worth, shielded from the audience by her robe, seemingly displayed her nude body to John Gielgud, who dropped to his knees before her while she uttered orgiastic cries.
Wikipedia foundation.