Buffy has such trauma around feeling like people she trusts could be betraying her. I wish they had really leaned in to Buffy not trusting Giles or resenting him more in s2. Her nightmare of him killing her in When She Was Bad, her lies to him in Reptile Boy, but then it just peters out. And I think one possible reading is that she wants to forgive him so much more than anyone else. In Lie to Me. Giles isn’t the one keeping this from her, Willow and Xander and Angel are. Giles shows up to comfort her and wins her trust back.

She wants a father figure who loves her and makes things okay for her so bad. Giles is always going to disappoint. Buffy will never actually be mad at him.