Ditto to what DC and Susan have said. IIRC, it was Anti-K who said something that cinched it for me about Perry knowing. The look on Perry's face when Superman asks Lois to go flying with him was more like he was giving his blessings to Lois and CLARK being together; if he had thought that CK and S were two different people, he probably wouldn't have shown disapproval at Lois' seeming fickleness, but neither would his expression have been so benevolent.
I hadn't, however, thought about the possible double meaning of this scene. The next time I watch this episode, I'll have to pay more attention to this possible interpretation. Well done!
Joy,
Lynn
