I'm reading it as this:
In the episode where Clark proposes, beautifully but desperately, to Lois, while she is dating Lex Luthor... What if, instead, events happen in this order:
First, Lois asks to see Superman. (Before Clark says anything to her about being in love with her.)
Superman shows up at her place; she confesses her love, asks if there's any hope, etc.
Clark, as Superman (and wanting her to love him as Clark), turns her down. But gently.
She's bummed. Majorly.
Clark then comes to see Lois as "the ordinary man", and confesses his love (probably much as in the episode).
Lois, having been hurt by Superman's response, reacts to Clark.
And then...
[write your story here and tell us all what happens
]
~Toc
EDIT: Ah, I see Sara got in with an answer first!