The Episode Heat

Heat-- Desiree Atkins gained the power of man controlling pheremones during the meteor shower while making out. She used them to seduce rich men to marry her (ie. Lex Luthor) and then seduce a patsy to kill them (ie Clark and the Johnathan Kent when Clark was immune).

So the story changed because...

The Pheromones failed on Clark. Likely due to being Green Kryptonite based, as Red Kryponite lipsticks in Crimson episode had a simialr effect and worked on Clark. So what if it was Red Kryptonite which gave Desiree her powers. Allowing them to work on Clark.

As above, but Clark reveals his powers to Desiree. Figuring out the potential of a superpowered boytoy, she keeps Clark to herself and uses another patsy to kill Lex.

Or she learns her pheromones have more abilities then she though. Controlling thoughts and/or emotions, lasting longer, it works on Clark, it works on both sexes and/or something else.

She could also discover something to enhance her pheromone powers. Kryptonite, something Lexcorp or Luthorcorp created, and/or something else.

Still more stories maybe available from this episode.