I'd like to think they might have bickering all the way through season 1 - 3, or had some very strange meet ups. I can think of various places I'd inject Amy as a "mystery girl" passing by just for fun. Such as Sheldon on Halloween in season one, where he meets her and totally backtracks because he's attracted to her and tells her he's a zebra when she says she likes his costume. Then she frowns with displeasure and says, "Oh, I thought you were the Doppler Effect," and walks off because she now has no further interest in him.

Those types of teases would have been funny.