"Oh ew. Well on the bright side Deuxi also had a slytherin phase and she totally grew out of it, he'll probably get bored of them as soon as he starts having math opinions they don't understand." 

"I guuuuessss. ... speaking of developing math opinions too cool for the Slytherins to understand I am lost reading this book Tri gave me, I think maybe he forgot I am not you, I have a list of questions?" 

"Oh yeah sure lemme see." 

"...and I guess Tonks is like special and impressive or whatever but it's really bad for social cohesion, you know, having to make exceptions--" 

"Is it? I wouldn't know, you're the expert on social cohesion." 

"Take Ed Bones, right. We love Ed. Ed loves everyone. It's such a waste of his talents and energy, a good supportive community would be helping him filter, you know? Like Prince, sure, staggeringly talented and her mom is only mildly an embarrassment, but like, some of the Ravenclaws who are barely worthy of the name- unlike you, of course- I mean, we call it a friendship quest because it takes effort. You won't help anybody if you burn yourself out trying to help the unhelpable." 

"I see, I see..." 

"So how's your Kestrels this spring?" 

"Oh, absolutely avalanched by the Wasps. Nobody's been able to touch them for ages. Sasha thinks they're cheating but I think Bagman's just really good." 

"Did you hear that rumor that they tried to get Darren O'Hare to play Chaser?" Daniel does not entirely know what this sentence means but it's really important to him to know things about his friends' interests. 

"Oh man yeah. Insane behavior. O'Hare is the best Keeper of his generation and just because he's good at strategy they want him on offense? No wonder we're bottom of the league. They oughta fire whoever suggested that and make him the manager." 

"Hey, I found that book you were looking for," is her opener, because she's had an entire year to figure out that the principal Ravenclaw/Slytherin interface API is 'if you do them a Favor(TM) they will be way less weird about answering questions or in any way acting like you might be academic friends.' She hands Karina a piece of noteparchment. 

"Excellent," says Karina, tucking the note neatly into her notebook. "How's studying for the charms final?", which means, do you have a charms question or a social question or a secret third thing?

"Oh, I am definitely not looking at even one single nother wand motion diagram," she says, which means, I feel prepared and don't need anything to do with that but it's more polite to claim to be tired of studying than to claim to think you don't need to do any more. "I was just wondering if you knew anything about what happened with my sister? Your roommate was, like, there."

Eyeroll. "Prince? Anytime anyone asks her about it she grumbles about how her precious studying time has been rudely interrupted with politics and then makes pointed vague comments about how whoever it was will probably regret their life choices but between you and me," which means this fun fact is your favor repaid, "I think she's just trying to sound ominous so nobody else rudely interrupts her from her insane quest to pass NEWT Potions before the rest of us even take OWLs. I bet she figures that whoever made idiot life choices is going to have Gryffindors happen to them anyway and she won't need to do anything. ... which, I mean, to be fair, probably not wrong."

Nervous giggle. "Wow I do Not envy anyone doing enough politics that that's a valid verb construction."

Karina would agree with this but actually this would be rank hypocrisy, as she is in fact scheduled to get started quite soon on doing the kind of politics where you happen to the Gryffindors as often and as violently as possible, so she just shrugs and goes back to her book.