Most people would be saying "thinking of marriage." A teasing, prurient person would have been saying "thinking of some OTHER stage?" But because it's Nozomi, unfortunately, what's really being said is "fucking off-stage."
Itou hachi ears! you get to keep your human ears too. that means nico is really as young as she looks and she will be maki's tiny childish clumsy loving servant while maki does intelligent and important things