It doesn't take him long to find it amidst the rest of his books and papers. He grabs it and rushes back downstairs, handing Rosy a slightly dog-eared white paperback book, with a geometric design on the cover, made to look as though it has been drawn and erased and redrawn and reerased many times. "How To Prove It" the cover says, and "A Structured Approach" in smaller letters underneath. "Here," he says as he hands it to her. 

"Oh," she says, petting the cover enchantedly. "It looks like a dust bunny! A big grumpy dust bunny!"

He raises an eyebrow and looks. "I suppose it does at that," he admits. Not at all how he sees it, though. "I think it's supposed to be like, someone trying to prove something, or something like that." 

"Well, they tried to prove something so hard they accidentally made an adorable cloud."

He snorts. "Fair. Anyways, open it up, to the intro, and we can get started?" He pulls up a chair, next to her, so they can both read. (Just as near as he is with those he tutors, sometimes, and yet it still feels far nearer than he should be. It's all in his head though. He brushes the feelings aside.)

Gosh. Proximity. She bumps her knee against his knee and then wiggles excitedly about it.

Right yes book. Book? Book. She opens the book.

The book intro starts off discussing the nature of mathematics, and the role of deductive reasoning, then quickly transitions into showing some example conjectures and eventually a proof about prime numbers, as examples of what's in store for the rest of the book. None of this is new to John, he's read this several times before, but it's probably new to Rosy, and so he keeps most of his attention on her, to see how she's reading and understanding and if she's interested or turned off by it. (Hopefully it's not too dense or confusing or too much too fast or things.)

For the first little while, bouncing intensity increases as book proceeds; then she gets into the parts that are dense enough she has to concentrate, and the bouncing becomes mostly background noise to her focus on the math.

He does the exercises at the same time as  her (it's good practice and helps him have a deeper understanding of the content) and helps her out and discusses bits if she needs it (which also helps his understanding of the content), but she's clearly a quick and clever study (and he had little to worry about, even if he's worrying anyways).

When he's working through another exercise side by side with her, a few minutes later, he hears the sound of the garage opening, and feels an overwhelming nervousness and an urge to hide everything quickly and pull out his school math textbook so they can be working on that math instead. 

She instinctively gives him a soft shoulderbump and only then realizes that perhaps it won't be as much of a comfort as she intended.

It's... something. The amount of comfort it is is complicated. 

The familiar sounds continue as the car pulls into the garage, the engine noise stops, and the garage door begins to descend. "We... should probably go say hi?" he says, voice uncertain. "Or I should?" 

"Don't look at me to decide, I'm not the local expert here."

"We can probably wait for him to come here, but then he might see that we're studying the book he got for me and not, like, the school textbook, and so he'll come to accurate conclusions?" He should probably make a decision sooner rather than later or it will be made for him. Unfortunately, he isn't sure what to do. 

"I feel like accurate conclusions are going to radiate from me like the light of the sun, but, up to you."

Aaaaaaaaaah. He is not keeping his cool at all. Why is he so worried about this? "That's probably fair. I could go greet him and then he could decide not to come see you at all and then not make any accurate conclusions?" This is silly and his choice is about to be taken from him. The door is opening anyways. "We can stay here, I'm sure it will be fine." He's not sure at all. 

Gentle shoulderbump.

"Hey dad!" he calls out as he hears the door open and his father come in. "I'm in the dining room with someone, we're working math together!" There, that's like, not a lie but maybe he'll draw the wrong conclusions, right? (Why is he so worried?)

His father comes in through the doorway, and looks at the both of them. He looks as he normally does when he comes home from work, wearing a polo shirt and khaki slacks.

"Hi!" she says, with a little wave. She may not quite be radiating accurate conclusions but she sure is much happier than most people normally are about math.

John is also somewhat happier than normal about math, so it's not like his Dad hasn't seen that before, probably? Still, he does look at them with a bit of amused suspicion in his eyes. (Oh fuck he knows.) "Another fellow student needing help with math? Nice to meet you, young lady," he says, extending his hand to shake hers.

"Nice to meet you too! I'm Rosy." She shakes his hand and then returns her attention to the book. Listen, it's a very good book.

John would perhaps prefer his Dad's attention not be drawn to the book by Rosy's gaze, but, well, too late now. "...that's not a school textbook, is it?" his dad says, still smiling in that annoyingly clever-looking way. 

"No, Dad," he says, doing his best not to roll his eyes or sigh with frustration. 

"My memory might be failing me in my old age, but I think I remember buying you that book, once upon a time?" 

"Yes, Dad," he says, unable to keep himself from sighing this time. 

"Interesting," he says. "Well, you two let me know if you need anything. You can stay for dinner if you'd like, Mom texted to stay she has to stay late again, so it's just the two of us, unless Rosy wants to join." He's still smiling and John wishes he would stop. 

"I think I'd better leave that up to John."

"...I'll get back to you," John tells him. "I think we're fine for now, you don't need to worry about us." 

"What is there to worry about? I'll be upstairs for a while to shower, so feel free to keep studying math until then." John's dad heads off, whistling tunelessly to himself. 

When he's gone, John sighs and drops his head to rest on the table. "Ugh. He totally knows." 

"Is that a bad thing? He didn't seem upset."

"He's not upset, he's delighted. And he's going to ask me all sorts of questions, and be insufferable, and probably embarrass me in front of you. Ugh. And he's going to tell mom about it, and she's going to want to know everything too. What do I even tell them about how we met, I can't tell them about the note or the fact that you apparently stalked me for more than a year or the fact that um, things I'm not supposed to talk about. And I still don't know how they're going to respond to you being a Blake..." This is a nightmare.