I like the title of "Confess" on this one. On the one hand it can be read as meaning confessing your love for someone. But on the other hand, it can also be about confessing your mistakes. Or it can be taken as a command, to confess.

Spoilers:
This one takes a little reading into. It seems like everyone in school knows Otomo-kun is socially awkward. After all, that's why he tried to half-ass his confession. The way Sensei blatantly teases him by accepting his confession in front of everyone shows that they were all in on the joke. No one would expect her to be serious. And the fact that the other teachers were making fun of him shows that no one took it seriously. They all knew she was trying to teach him a lesson.

But there was some truth in what she'd said about being pleased that someone confessed to her (even if she knew it was an accident). So, when he reacted so strongly to her, she just couldn't resist going further. She was probably going to stop after sucking him off, but again that strong reaction. It really pleased her.

She's interestingly complicated. She starts the last page with kind of owning him with that kiss. Then acts like nothing happened and as if she's finally going to let him off the hook. Forcing him to say what she stopped him from saying earlier. And then she hits him with that double negative that made it impossible to actually admit he made a mistake, even if he wanted to. And that's checkmate. Women can be delightfully complicated, can't they?