"I only know your abilities by reputation," he murmured, pleased at her newfound poise. "I never assume if I can help it." He likewise snags his own champagne flute, holding it up to the light as if to admire the color. "Shall I find us a seat?" He is asking how long she needs in order to finish making the switch, and how much time her concoction needs to take effect. And whether or not they should stay to follow through.