Simon feels antsy and upset when he gets home. He thinks that Leah is often mad, but this feels worse than normal, and he's never seen her cry before. After dinner, Simon listens to music in his bedroom. Around nine, Mom and Dad knock and ask if they can talk. They establish that Simon shouldn't get drunk, and then Dad apologizes and says that Simon was right to call him out about making gay jokes. Dad says he loves Simon, no matter what. He says that Simon can always rein in him and Mom, and admits he knows he didn't make it easy for Simon to come out.
Simon's inclusion of the fact that Leah is often mad suggests that Leah may feel extremely insecure in her friendships, more so than Simon realizes. Again, this means that Simon and Nick may have to reevaluate how they interact with her to give her more of what she needs. Dad's apology shows that not all the Spier family's changes are bad—not making jokes about gay people is an inarguably positive change for the whole family.
Simon says he only hesitated to come out because he knew Mom and Dad would make it a big deal. Simon insists that they make a big deal out of everything, from him drinking coffee to shaving. Mom laughs and tries to explain that when Simon was little, she got to watch every tiny change he went through, but now she misses things. She agrees that he should be changing. She asks that Simon keep them updated about his changes, and promises they'll try to not be weird about it. As he stands to leave, Dad tosses Simon his phone and says he can have his laptop back if he remembers his lines for the play. He doesn't care that Simon doesn't have any lines.
This conversation between Simon and his parents shows both parties sitting down to truly understand each other and relate as equals, especially in the way that Mom agrees to Simon's terms. This suggests that there is definitely room for Simon's family to evolve to accommodate his changes and those of his sisters as well. Taken together, this conversation suggests that familial harmony is contingent on truly listening and getting to know family members on a deeper level.
Simon is nervous on opening night. He changes early and waits for Abby to arrive so she can do his eyeliner. She's in a strange mood when she arrives and answers Simon's questions with one-word answers. As she begins to draw on the eyeliner, Simon asks if everything is okay. After a minute, Abby asks what happened with Martin. Martin already told her what happened. Simon says he didn't tell anyone about the blackmail and didn't feel as though he had a choice but to go along, even though he knew Abby wasn't attracted to Martin. Abby insists she gets it, but when she finishes his makeup, she tells Simon that he doesn't get to make decisions about who she dates. Deflated, Simon apologizes.
Simon finally realizes that in some sense, he did exactly what Martin did to him by trying to manipulate Abby out of his own self-interest. By attempting to facilitate a romance between Martin and Abby, regardless of Abby's feelings on the matter, Simon tried to take away Abby's agency to preserve his own flimsy sense of control. The fact that Simon was ineffective in doing so only reinforces the novel's assertion that taking away someone's agency like this is can only end poorly, and doesn't help friendships in the least.
The play goes well, but Abby disappears immediately afterwards. Simon feels miserable. Dad gives Simon a ridiculous bouquet and asks on the way home if he's friends with Martin. Simon feels blindsided by Abby's anger. He gets that nobody can be forced or manipulated to like someone, and he of all people should know that. He feels like a terrible friend, but also reasons that whatever Martin shared with Abby, he didn't mention Blue. Simon reasons that this could mean that Martin isn't Blue.
Again, though Simon certainly isn't required keep his parents in the loop about what's happened with Martin, by not telling them about the situation, Simon is forced to listen to his dad express interest in Simon being friends with his blackmailer. This makes the case yet again for more openness between people who have close relationships.
Simon gets his computer and logs into his secret email. He suddenly realizes that every email from Blue is time-stamped, and most were sent while Simon, Martin, and Cal were in rehearsal in the auditorium, where the internet is blocked—so Blue can’t be Martin or Cal. Simon reads all the emails and feels as though he's falling in love with Blue all over again.
Having Blue's anonymity reinforced allows Simon to divorce all the ills of Martin and Cal from what he knows of Blue, essentially letting him start fresh. This gives Simon the opportunity to stop making assumptions about who Blue is and instead, let Blue tell him who he is on his own time.