Even without the demons crashing, cursed masks, and boyfriends of Buffy that make parties less then fun Giles is not a party person. But he's trying, because... well it seems to be mor friendly then being alone in the Magic Box or library while the others are at a party.

"I've never been to a block party before. It seemed to be the thing to do." He looks down at her, an eyebrow raised. "I'm at a loss as for what one exactly does at a block party, though."