Season 4
"Goodbye, Iowa"
Giles: Yes I can't imagine why I didn't sleep well in my beach ball.
Anya: Every time you moved it made squeaky noises. It was irritating.
Giles: Really. I'm surprised you could hear it over your Wagnerian snoring.
Buffy: Ok you guys, could we not please? Everything's screwed up enough without you two doing scenes from my parent's marriage.
Anya (to Giles): Sorry.

"New Moon Rising"
Giles: So the activity's shifted but not stopped. That's fascinating.
Anya: To an extremely bored person, maybe.
(Giles looks annoyed)

Anya: (smiles and holds up hand) Slap my hand now!
Giles: Beg your pardon?
Anya: In celebration
Giles: Oh... Yes (slaps her hand)
Anya: Ow!