He never would have guessed she'd come to him: Giles barely knew Anya. But somehow her faith that he would ride to the rescue made him feel capable of absolutely anything – including wielding a chainsaw, which, quite frankly, was one of the more terrifying experiences of his adult life.
After her reunification with Xander, Giles was stunned to find himself jealous. Not in a strictly literal sense, of course! But she looked at that boy like he was the centre of her universe, and no one had looked at Giles like that for a very long time indeed. If ever.