Buffy always had this fantasy of having sex with giles on the library table at SHS.
(3rd season)
And that didnt happen, cause well, they had to blow it up.

Giles always had this fatasy of having sex with Buffy on the research table at the magic box
(5th season)
But that didn't happen, and Willow destoyed the magic shop.

(Or you can switch it, & say Giles fantasized about the library, & Buffy fantasized about the magic box).

Love trish
Who has an evil mind, i know :)