What is the theme in Fool for Love by Sam Shepard?

Many of the memories Eddie and May share are of a sexual nature. Their feelings of love, hate, and jealousy drive Fool for Love. Since the moment they first met, before they knew they had the same father, Eddie and May have had a mutual passion. Though Eddie claims to love May, he also is involved with another woman, "the countess" as May calls her. During the course of Fool for Love, this woman shoots out Eddie's windshield, sets his truck on fire, and frees his horses—all presumably crimes related to her sexual jealousy. Eddie wants to continue his affair with May—and possess her sexually as he has in the past.