Naked on a Broadway stage, Audra McDonald is on high alert, all of her senses sharpened.

She likens it to a fight-or-flight response, and it happens eight shows a week: her body’s reaction to being so exposed, center stage in a 1,200-seat house.

“Maybe strippers get real used to it,” she said recently in her dressing room at the Broadhurst Theater, “but for me there’s nothing normal about that. So there’s nowhere in my mind that I can drift off and let this just kind of happen, because everything about it is demanding that you be present.”

Opposite Michael Shannon as the lonely, damaged Johnny, Ms. McDonald plays the broken Frankie in Terrence McNally’s 1987 two-hander, “Frankie and Johnny in the Clair de Lune,” which opens with the graphic sexual ecstasy of the couple nearing climax. Then Frankie tumbles, laughing, from the bed.

Surely the scene has always been delicate to stage, but perhaps particularly now, with the post-#MeToo heightening of sensitivities about the potential for exploitation of actors, especially women. It’s partly thanks to that same movement, though, that the nascent field of intimacy direction is taking off. Now, with “Frankie and Johnny,” it’s come to Broadway.