At least four people conclude that Bella and Celo have had sex and mention this to Bella. The fact that the door was open the entire time he spent hanging out in her room is apparently immaterial (since she wouldn't have been breaking any rules if she'd had sex with him that way, and no one was loitering in the hall supervising them the whole time). She contradicts them on this. Three people don't believe her. Miki does, and is immediately promoted to Bella's favorite out-of-class friend.

In Intro Psych for Subtle Artists, there's a discussion of what subtle artists do with their own minds, and how this differs from everyone else. Bella has already talked to all her subtle arts professors about her own peculiarities, and Professor Murray has her talk a bit about how she's used lucid dreams for introspection, self-modification, and memory boosting. Professor Murray then explains that people who aren't subtle artists can only rarely lucid dream, and even those who can don't find it an effective jumping-off point for any heavy-duty self-searching.

One of the elves in the class looks at Bella oddly through her little talk.

But she doesn't say anything, so Bella ignores her.