"i don't like sirius" that's embarrassing, keep that to yourself

Sirius got a full-body reaction the first time he saw James as the quidditch captain and snapping orders around.

Euphemia Potter ships Prongsfoot harder than anyone. When they got together she pulled out a colour coordinated file of potential wedding venues and flower arrangements.

most difficult problem of writing fanfiction is when you need a character to express the particular surprised/dismayed/disappointed sentiment of going "jesus christ" but this isn't a lore friendly thing to say and there's nothing lore friendly that conveys quite the same emotion

Sirius and James are each other’s exception. Sirius is harsh with everyone except James. James is arrogant with everyone except Sirius. Even people who dislike them can’t deny their love for each other.

The only thing Prongsfoot fight about as a couple is their mutual insistence on constantly trying to die for each other.

Whenever sirius leaves a room full of people claiming he needs 'alone time' he always takes James with him. When someone points out it's not exactly alone time if somebody is with him, he looks at them like they have no idea what they're talking about, because of course his alone includes James, why wouldn't it?

Sirius loses the power of speech when James calls him Pads in bed

James threw Sirius over his shoulder in celebration after a match one time when they were 15, and consequently developed a life long obsession with manhandling Sirius.