On Christmas Eve, Simon feels as though things are off despite the fact that his family has observed all of their typical traditions. The family sits in their pajamas in the living room, participating in a Facebook scavenger hunt. They have to find friends on Facebook who are on vacation somewhere tropical, posting about breakups, or posting about being Jewish on Christmas. When Simon reads a classmate's status out loud about having a perfect night, complete with a winking emoji, he thinks it's gross but he also cannot stop thinking about Blue signing his emails with "love." Alice receives a phone call, leaves to take it, and is gone for two hours. The scavenger hunt fizzles.
Despite the fact that Simon can't pinpoint what's different about Christmas Eve this year, it's worth noting that this is the first year that Alice lives away from home and is only coming home for holidays. This represents a major change, and Alice's phone call also indicates that she has a life away from home that is clearly influencing how she interacts with her family.
Simon gets a text from Leah that she's outside. He goes to let her and Nick in and finds them standing awkwardly on the step. They suggest they take a walk, and Simon detects something strange in her tone. Simon changes and grabs his dog Bieber. Before they're even out of the driveway, Leah asks Simon if he's okay in a strangely gentle voice. Simon knows something is going on, but neither Nick nor Leah will tell him what. Finally, Leah decides she's leaving and walks away. Nick stands with Simon for a minute, but still refuses to tell him what's going on. Simon thinks he's never seen him look like this. Nick touches Simon's arm, which he never does, and wishes him a good Christmas before heading back to his house.
As obvious as it is to everyone involved that there's something up, Nick, Simon, and Leah's habit of not talking about important or personal things prevents them from actually addressing whatever's going on here. Despite all the places where this interaction falls short, it's also important to note that Nick and Leah are trying their best to show Simon that they care about him. Nick's unprecedented show of physical affection suggests that their relationships are going to start to change.
Simon's family has French toast for Christmas Eve dinner on nice china, per tradition. Simon still feels as though things aren't the same, and thinks he's felt this way all week. He wonders if it's because Alice is at college or if it's because he's spent his week pining over Blue, who isn't ready to meet in person. After dinner, Simon joins Nora and his parents in the living room to watch a movie. He squints at the lights to try to make them look like he remembers, but decides to go upstairs to listen to music.
Though Simon's suggestions as to why Christmas feels weird are certainly contributing factors, it's also true that this is the first Christmas for the Spiers where their children aren't actually kids anymore, a shift that naturally comes with changes. Simon also isn't helping to make things feel the same, given his decision to not participate in the movie tradition.
Soon after, Nora knocks on the door and lets herself in. She reaches for Simon's computer and says she needs to show him something. Simon snatches his computer from her, but does as she says and navigates to the creeksecrets Tumblr page as she settles in beside him on the bed. Simon stops dead when he finds a post, seemingly written by him, announcing his sexuality and his sexual availability to any interested guys. The post makes sly references to Blue. Nora explains she already reported it, and Simon knows that Martin did it. He hopes Blue hasn't seen it.
Nora's decision to bring this to Simon's attention reinforces that the relationships between the Spier children are changing, especially since this entire interaction seems unprecedented. It also tells Simon that Nora absolutely cares about him on a deep level, which illustrates that she's going through a similar process of coming of age and recognizing others, even if Simon isn't as aware of it.
After a few minutes, Simon says it's true that he's gay. Nora said she could tell from Simon's reaction to the post. Simon insists he can't do anything but wait for the administrators to take the post down. He says he thinks that Nick and Leah already know, and he insists he doesn't want to deny the fact that he's gay. He becomes suddenly angry at Nora when she tries to tell him that people would be okay if he came out. She hands him his phone, which shows notifications of multiple texts from Abby assuring him she didn't tell anyone.
Though Simon has somewhat of a choice here to come out to Nora, it's also largely forced on him because of the Tumblr post. His (justified) emotional reaction to this illustrates the negative consequences of having admissions like this forced upon someone, rather than that person actually being able to control when this information gets out.
On Christmas morning, Simon wakes up relatively early. He sits with Bieber on the couch until everyone else gets up, thinking about Blue. Everyone else is up by nine, and Mom makes a big fuss when Simon pours himself coffee. Simon thinks his parents are so against any changes he makes, and reasons it'll be a big morning for them if they're even interested in his new coffee drinking habits.
Though Simon is understandably in a bad mood, he's also hyperaware of the way his parents fixate on his changes. This suggests that Simon is struggling with the changes himself as well as the surveillance of those changes, emphasizing that making these changes isn't easy to do.
Everyone opens their presents in a frenzy of paper and bows. When all the gifts are opened, Simon tries to casually tell his family he has something to talk about. Dad starts joking and suggests that Simon is either gay, pregnant, or got someone else pregnant. Simon plays along for a moment before saying that he is indeed gay. Mom and Alice are happy and proud, but Dad asks which girlfriend turned Simon off of women. Alice calls Dad out, and Simon thinks that these reactions are exactly what he expected.
Even if Dad means his reaction comment as a joke, it does imply that being gay isn't normal and instead, is something deviant. Even if Simon expected reactions like this, it doesn't make this any easier to hear and shows that just as Simon is growing and changing, Dad will also need to think more carefully about his words if he wants to keep from alienating his son.
Later, Alice follows Simon into his room. She refuses to let him put on his depressing playlist aptly titled "The Great Depression" and insists that they can talk about boys. Simon asks Alice to tell him about her boyfriend and Alice grudgingly says his name is Theo. Simon immediately pulls up Facebook to find him, and Alice tells Simon to stop—this is why she didn't want to tell anyone in the first place. Simon gets it, and Alice promises to tell Mom and Dad about Theo.
When Alice asks Simon to not search for her boyfriend online, it makes it clear that Simon isn't the only Spier child who has a hard time with Mom and Dad's interest in their children's lives—and it shows too that Mom and Dad's interest drives their children to keep secrets in attempts to not be made to feel uncomfortable about perfectly normal changes.