I always saw Jimmy as kind of a young stud *ahem* I have a more impolite word, but we're on the gfic board. lol
He's young. As young people, we fall in and out love every five minutes.
As for the Smallville thing, I didn't elaborate on it in the story because it was more just to signify that they'd moved forward in their relationship to the point where Lois would *willingly* go to Smallville, though I keep wondering what I could have done with that story line if I'd run with it. lol