 Why does Roger allude to Tristan and Isolde when confronting his wife and Cass Gordon?
"But he doesn't have to—have them," objected Olga. It arrived before the meal, materializing against one of the seven walls of the roofless chamber. Tennant watched the girls as a sweet-voiced crooner began to ply an unfamiliar love lyric to a melody whose similarity to a thousand predecessors doomed it to instant success. Olga sat up straight, her pale blue eyes round with utter disbelief. Dana stood almost in the center of the room, carmine-tipped fingers clasped beneath the swell of her breasts. "In the one instance, we're the hunters, the breeders, the trophy collectors. He had felt the inner tug of command, said good-by to the women and returned to his smaller compound within its own barrier dome.
 He knows that his wife will ultimately choose Cass Gordon over him.
 He knows that Cass Gordon and his wife will both be transported to the fourth dimension.  He knows that his wife will ultimately choose him over Cass Gordon.  He knows that Cass Gordon and his wife will never get to be together.  He knows that his wife will ultimately choose Cass Gordon over him.