I've always wondered, did Lex know that Superman was faking it?
Ooooohh! That's a good question! Someone could absolutely take that idea and run with it as a new twist on PML. Lex now knows that Superman wants Lois, and it motivates Lex to start making his move on Lois as a way of stealing her from Superman. And maybe Lois keeps dwelling on the fact that Clark wasn't affected by it...gosh, Superman wants me, but Clark doesn't?! And it starts to really irritate her, until she tells Clark off for not being in love with her, because it's just not possible that she could be attracted to him when he feels nothing for her. Cue Kerth nomination for Best First Kiss / Best Revelation.