Who's Afraid of Virginia Woolf? Steaminess Rating

Exactly how steamy is this story?

R

There's no actual sex in this play. However, Martha attempts some heavy petting on stage with her husband George, but he rejects her. We see her blatantly make out with Nick. When the two go upstairs to consummate, however, Nick is unable to perform. Even though there isn't any actual sex in the play, we still give it an R rating for its sexually suggestive language and mature subject matter.