There we go, that's better.  Relaxed people are less likely to throw out insults they don't mean.

She stifles an urge to pet him.  He probably wouldn't like it, at least if it's unsolicited.

Now: bonding!

"...Wow, you might have a meaningfully worse home life than I do if you actually mean what you said.  Even if my dad's an abusive prick that I never want to see again, my mother found it in her to apologize for the shit she did once I gave her worldview a good shake, and it sounds like your folks wouldn't, even if you knew how to.  Which is bad.  People should care about other people.  ...Do you have siblings?  I don't, but maybe you and Lily could commiserate."

...This is totally bonding, right?

Sirius tries to imagine his mother apologizing for anything. The mental image is sort of fascinating in its absolute wrongness.

He blinks at Ophelia, and repeats back, bemused, "people should care about other people, huh? I mean, they sure don't, but yeah, I guess, that'd be nice, wouldn't it." The tone with which he says this suggests he thinks she's incredibly naive. "Maybe then there wouldn't be a war, eh?" 

but they do, they do, if you love them back, you know this, I know you do, please -

"Oh, yeah, I have a little brother. He's a dumb baby who thinks our parents are right about everything, it's terrible."

Lily considers this. "My big sister is also kind of dumb and terrible but she is still my sister."

"Heh. Wonder if Rex'll still think I'm his big brother if I don't go to Slytherin. All my family are, yours too?"

"....oh, she's not here, she's not magic, that's why she keeps being terrible is she's jealous."

"Oh, that's why I've never heard your name before! You're - "

Sirius is just barely aware enough that mudblood is a slur to not say it to Lily's face while trying to make friends with her, he's heard his cousin Bella say it and obviously mean target, victim, worthless, but he ... doesn't actually have a replacement vocabulary word to hand, and stalls out awkwardly in the middle of the sentence.

Ophelia knows that it's a naive belief, that people should care about people.  She just believes it anyway, because fuck people who try to tell her she shouldn't care.

"Both of her parents are Muggles, yeah.  ...I don't really know why that word exists, honestly, it sounds as bad as the way most people use queer."

"S'posed to sound bad, isn't it, that's the point."

"...The utter disdain wizards have for nonmagical workings is honestly rather bizarre, in my opinion.  I get that you broke off back in the Middle Ages, but - has anyone thought to poke their head out, since then?

"Probably not, you think you have everything.  You don't need jet planes, you can teleport.  You don't need - mail sorters - you have magic owls.  Somehow.  But - I can't help but think that there's places where wizards could benefit from lifting Muggles' notes and updating the things they use and make.  It's only Muggles that've been to the Moon, as far as I know."

There's actually a whole section of the International Confederation of Wizards' department of secrecy enforcement which is devoted to the regular retrieval of the dead bodies of wizards who figure out how to teleport to the Moon but do not figure out that a bubble-head charm is not remotely rated for hard vacuum. They hand out little frosted grey cupcakes to the roughly one in every hundred of these intrepid explorers who survives long enough to instead be retrieved alive and immediately arrested for gross violations of the Statute of Secrecy.

Sirius is blissfully unaware of this, due to being eleven, and also due to being the exact type of person that is the reason the whole thing is classified in the first place.

Ophelia, not having access to wizarding documentation, hardly knows either, and it's also not like that counts.

It does prove her point quite handily, though!

In any event, in reference to learning things from mundanes: "Oh, probably, yeah, but then they'd have to talk to them without committing secrecy crimes every twelve seconds and that's apparently really hard."

"Your fashions are a crime upon themselves, for sure," she quips.  "But really.  Send a wizard who can blend out to buy an encyclopedia sometime.  I'd do it myself but I'm broke."

Sirius stiffens instinctively and makes a spluttering offended how dare you noise, and opens his mouth -

nooo you like fashion!! talk about fashion!!! bonding!!!! please for the love of fuck

- and then remembers to look down at the actual clothes he's currently wearing, which is not the usual dozen layers of tailored, embroidered glittering-black-thread-on-black-silk that his father refuses to let him leave the house without. (That staggeringly expensive outfit is currently shoved haphazardly into his equally expensive trunk, tossed into the luggage rack in Andy's compartment before she cheerfully kicked him out so she could make out with her boyfriend.) He's instead draped in a variety of stolen, dyed, shredded, etc. shades of eye-searing mismatched neon, and also, for ironic contrast, his black uniform hat.

"In my defense," he says, grinning crookedly, "this objectively terrible outfit is specifically designed to annoy my dad. I waved at him through the window and he made such a face. ... What is an encyclopedia?"

(Wizards do have those, sort of, but Sirius is not an enormously library-inclined child. Even if he were otherwise inclined to be, the library in his house tends to contain Aunt Cassie.)

That gets Ophelia to grin.

"Your outfit honestly knows what it's doing, so it can stay; it's very punk.  I'm more talking about the way that in general Madam Malkin hasn't met a color she wouldn't pair with literally every other color ever.  You ought to at least consider the rules of fashion before you break them!

"Oh, and an encyclopedia's a collection of books that're basically supposed to tell you the basics of everything.  Science, math, history, culture, art...Kind of like a dictionary, but with a wider remit."

Huh. He was fully expecting to be insulted just there - at absolute best in a friendly ribbing way, Andy smiled at him while she was saying oh my god, sirius, what are you wearing but still - and instead: this.

Yeah maybe they can be friends actually? 

"Oh, you're so right," he giggles. "I think Madam Malkin might be color-blind, she's just, like, really good at making the fabric go into shapes. And of course also the Dumbledore school of color theory is in vogue now." He says Dumbledore with a sort of habitually derogatory tone and then visibly reconsiders it as soon as it's out of his mouth with a thoughtful tongue-click. "I mean, my parents hate him so probably he's a cool dude. But still! Why is he like that! If I was the most powerful wizard in the world I'd want to look awesome about it!"

And as something of an afterthought:

"Oh, that's a cool kind of book for there to be. We should see if Hogwarts has one and then you can check if the Muggle ones have extra things in them."

"That's the tall guy with the doom face and the super long beard? I thought he looked awesome," Lily interjects. "Very wizardy."

"He's - he's definitely very something.  I don't know why but - I think he's sad.  ...Why do I think he's sad, that's a weird thing to think about a guy who was very visibly emoting fury and threat - oh, he's in charge, isn't he, and he has to deal with all this...whatever that's happening, instead of - teachery stuff, which he appears to want to do.  Since he's working at Hogwarts and not, you know, anywhere else.  That makes more sense.  ...Probably shouldn't trust that guess further than I can throw it, though, it's not like I know him from Adam."

... huh.

"Yeah, he's the headmaster," nods Sirius. Catches Lily's puzzled and fascinated encouraging nod, and adds in her direction, helpfully, "famously rejects like a million galleons in job offers a year to keep being headmaster, even. Dunno how true it is that he's just doing it so he can sabotage all the Slytherins, Bella says that all the time but Andy says she's just mad she failed her transfig NEWT."

"...Are a lot of the...sides in this war, do a lot of them come up through whatever Slytherin is?  Like your asshole relatives?  'cause I kinda get why he wouldn't like your relatives, if he's anything like I think he is."

Squint. "Whatever - ? Oh damn you have been like zero invited to anything haven't you. Did your mom personally insult Phil Greengrass to his face. Oh wow. Okay." He runs a hand through his hair. This is both an anxiety fidget and a deeply practiced motion: it results in a nearly picturesque perfectly artful dishevelment. "Okay. So. So the way this works right now is like - Hogwarts has four Houses and supposedly you get sorted into them by personality or whatever and - yeah, basically? The war is Slytherin vs Gryffindor, the other two are kinda sorta neutral but not really, and Dumbledore's a Gryffindor and my whole family's Slytherins and your whole family's Slytherins and - " considering pause. "Not everybody is good people or Death Eaters, right, but - that's why I want - something else."

"Huh, I was supposed to be getting invited to things?  What am I, wizard famous?  ...Though just guessing on the - look of it, I bet mom marrying a Muggle, for reasons I don't understand - because he's a prick - didn't endear her to - whoever it is who makes the invite lists."

"Ah. Yeah that'd do it. Normally it's like - you're not on the sacred twenty-eight," he says this phrase while aggressively rolling his eyes, "but Princes would normally get invited to things still, like the Crabbe-and-Goyles and stuff, but not if - "

(what even should you do, actually, if you are stuck halfway, a pureblood name and a Muggle father, you cannot be Andromeda Tonks, you cannot be Lily Evans, you cannot be Gideon Prewett, how are we to know what Ophelia Prince could possibly have done, no wonder she - no wonder she - fuck- )

Andromeda fucking whomst, what -

" - yeah so I want to say that if I was you I'd put on my Muggle dad's name just to annoy the shit out of everyone and be really good at things anyway, just to prove the point, but if he sucks then like, valid not to do that? I guess?"

"Hmm.  You do have a point.  Well, I have the whole train ride to decide whether I feel like pissing off whoever the Death Eaters are!"  This said cheerily, without a hint of external concern.  "Though I imagine I'll need self-defense practice, if I do do that, in larger quantities than expected."  And there's the realism.

" ..... yeah. Probably." He glances at Lily, who is currently engaged in speedreading her Charms textbook while listening avidly to this conversation. "Some kinda defense, for sure." He pauses, and considers, and then pulls a deck of cards from his pocket. "Exploding Snap?"

This is not only a game. It is a reflex training exercise.