It would be nicely symmetrical if the thing that drives Lana *away* from Lex was seeing the consequences of Lex *uncovering* some of CLark's secrets (and maybe doing bad things with them), leading Lana to realize that some secrets really *do* need to be kept.

Or, alternatively, for Lex to keep his promise of honesty to Lana and have her driven away because she finds that she actually can't abide some of the choices he makes/things he does. I think that would also be an interesting way to go because it would leave *Lana* alone because of something she always insisted relationships needed -- full and total disclosure. That would actually be another way for her to learn that sometimes, the things people keep from you, they're keeping for reasons of allowing a relationship to *survive*. It would also tie in nicely to something Lex said to her in Recruit, which is this idea that sometimes, people claim all they want is the truth, and then when they get it, they wish they'd never learned it.