My understanding of the story (please correct me if I am wrong, Queenie), is as follows:
Clark's Kryptonian biology permits him only eight months of fertility (not a good trait for the survival of the species). Cat had somehow found out that Clark is Superman. He wishes to have a child, but he is still holding onto the notion that he wants Lois to love him as Clark, and so he is reluctant to tell her his secret and ask her to be the mother of his child. (The timing is wrong.)
What I don't understand is Cat's motivation for agreeing. Her character as depicted in canon doesn't seem to me to be the sort who would be willing to "let her body go to pot" so that she could help Clark out. (Please note: That quoted phrase is how I think *she* would think about pregnancy; it is *not* my personal opinion.) But I'm willing to overlook a lot of character inconsistencies in a comedy piece that would bother me in a serious story.
Joy,
Lynn
