Oliver definitely didn't have the monopoly on saying stupid things.
"Um." Charlie said again. "Yes." Yes he had kissed back. Because he'd wanted to. He still wanted to, but stronger than that impulse was the panic clawing at his throat, the realisation that he had just kissed his best friend. His best friend who was quite probably in love with him, and very definitely deserved someone better than Charlie.
"I-I can't," he stammered, forcing his fingers to uncurl from the back of Oliver's coat, sliding down his neck. "I-" cheeks flaming brighter than his hair, Charlie stepped back and disapparated with a rather disconsolate 'pop'.