Misinterpretation or overinterpretation?
"Gathering together a few necessities, Tristan and Isolde retreated into the woods where they found refuge in a cave, a cave that had been cut into a mountain as a place of refuge and love-making in heathen times. This cave became their temple of love. Its altar was a bed made of crystal. Tristan and Isolde lived together in this cave for many days, sustaining themselves, some say from hunting, but others say from love alone.
One day their solitude was interrupted by the sound of a hunting party: horses, hounds, and horns. Suspecting that the huntsmen might discover them, Tristan drew his sword, then placed it naked between himself and Isolde as they lay there on their crystal bed.
King Mark himself was in the hunting party, and just as Tristan had suspected, one of the huntsmen discovered the cave and peeped in through an opening. Observing the two lying on their bed, separated by a naked sword, the huntsman ran to King Mark and reported what he had seen.
Mark came and saw for himself his wife and his nephew separated by a sword, and he assumed that this could only be a sign of their fidelity and loyalty toward him: her fidelity as a wife and his loyalty as an honorable knight."
D. L. Ashliman