It wouldn't work for future Clark to have sex with past Lois. It may get her pregnant, but it wouldn't give Clark the dreams he kept mentioning in "On the Other Hand."
And then, even when Christopher DOES look like Clark, Clark wouldn't have ANY REAL REASON to believe Christopher is his son.
My guess is future Lois and Clark are just going to make sure past Lois and Clark "get in the right position" so it will happen.
EDIT: Of course, maybe that wouldn't really matter. Clark would have married her in Latislan, regardless. And I argued in the "Other Hand" thread repeatedly, that it SHOULDN'T matter to Clark that he didn't think he was the biological father.
But Carol wrote it that as far as the "connection to Earth" issue, it DID matter to Clark. So shouldn't they give them the opportunity to realize that?
Oh, and I meant to say that I love Tempus. He thinks he's got everything figured out about how he can ruin their lives, one way or another. If he really wanted to ruin them he would:
(1)Not give them the opportunity to go back. Lois and Clark hate having to choose, but they also know their sons mean more to them then Ellen, Lucy and Dave, as much as the hate the fact that they may not survive. It's what Tempus gets for not having children. He doesn't understand that at all.
(2)Set the time machine so the could ONLY recreate the accident. The way he has it now, he's giving them the opportunity to change other things (even though he doesn't notice it).
I don't know if it will work, but it seems to be working so far.
That's the perfect protrayal of Tempus, though. He's always so cocky with his villainious plans that he doesn't see that Lois and Clark may find a way out.
