Oh my God—this was amazing. From the prompt and the title, I totally expected something funny and light, and while you definitely delivered there, you've done so much more. The beginning is great, with all the anecdotes about Sirius becoming briefly obsessed with something or other (I tend to do the same thing so I could really relate) leading so naturally into the first bit of dialogue. I loved all the dialogue, and really felt as if I was inside each scene, not just observing from a distance. Your characterizations were perfect, especially Sirius's tendency to throw himself headfirst into things and his refusal to give up and Remus's good-natured way of dealing with Sirius's obsessions. A couple of my favorite bits:

“It’s not as easy as-“
“You don’t make it look very easy, Padfoot,” Remus says in a casual voice as he walks over to the kitchen counter.

And

“I’m not trying to make fun of you, Padfoot. I sort of wish I was, but I am genuinely asking.”

The way you brought the war in was seamless, as was the revelation that Sirius used knitting as a way to lighten the mood and bring them closer together, and the stuff about the names, which rang so true and just hit me in the gut. And the ending—good God, you're brilliant and you broke my heart. As many Remus/Sirius angst stories as I've read, it's hard to do that in a way it's not been done before, but you managed with flying colors. I love, love, love this story.