So I was rewatching D.O.C last night and noticed something very interesting:
This is part of a flashback near the end of the episode.

SUN: Jin, I love you.
JIN: Madly?
SUN: Madly.

Pretty interesting, huh?

What do you all think? Is their any connection to Sam and Sonya?

Really?
That's very interesting ...

I believe Sun and Jin say it to each other in an earlier epi, too. I can't remember which one - maybe someone else does.

As for why they say it and Sonya says it to Sam, I haven't a clue other than the writers seem to enjoy having the characters swap phrases and lines. Or maybe they all loved the Doors song "Love Her Madly." :shrug: