Ooo! People remember my little [or not so little!] fics?! So nice!
In LtL it's... a little while. I forget how long, but not terribly after the wedding. They'd known each other, gosh, 6 or 8 years at the time.
In OtOH it's a bit longer iirc. They'd met in late August. Got married in early Jan in Latislan and he told her over spring break - which I think was in March.
As for the longest one I remember... Gosh. There was Coming of Age where a high school Lois and Clark meet as camp counselors and when she gets home she finds out she's pregnant. He raises their son for... 7-8 years? before she returns and he tells her at some point not too terribly long after that.
