Loved the part.

I think Lois's reaction is perfectly reasonable. There are two issues:
1. The fact that Clark is Superman and therefore an alien.
2. The point that Cristina made so well. This section covers it:
Quote
"Who else knows about this? Perry White? Mayson? Half of Metropolis? Your friends?"

Clark shook his head. "No one knows. Just my parents ... me ... and now you."

"No one?" she whispered. "Not your colleagues? Not your former girlfriends? Not your cousins? Not the neighbour's kid you grew up with? *None* of them know?"

"No."
I think this part had more to do with Lois asking him to leave than the fact that he's Superman. The "relationship seriousness" meter just pegged at the top of the scale. Lois needs to know what she thinks about that.

Bob