Well I agree that Clark shouldn't be counting the years until he can divorce Lois, particularly after making love with her, I also think assuming he would agree to stay married to Lois would assume that sex solves everything.
And it doesn't.
Certainly it helped Clark realize he has some feelings for Lois, but they have a lot more to work through than just that.
It's not going to be wrapped up in a big bow because they had a roll in the hay, even if it DID mean something to both of them.
