Xander’s father had vomited in Buffy’s purse then he hit Spike. Spike hit back then all hell broke loose at the reception. Spike pulled back at the last second expecting the chip to fire or Tony would’ve been killed not simply knocked out.
Everyone thought at first that the chip had misfired and caused some kind of seizure. Spike just stood there frozen for what seemed like an eternity. “I'll leave,” he said.
“What! Why, and where would you want to go without me?” Buffy asked.
Spike was almost crying. “The leash broke.”
“William, you’re my equal not my pet.”