Author's Note: Blame all of this on one Merry [That Guy Who Died] for pointing out all the reasons why Remus & Sirius make the most adorable couple ever. I don't even LIKE the Harry Potter series. But I digress. If I was forced at gun-point to admit my 2 favourite characters, they'd be Sirius & Remus. So there you go. Comments are my drug, so be a dealer.
The Reasons Why
If James ever asked why Sirius chose a dog form as his Amagi, he'd say that because he knew Remus would need someone to keep him in check, and James wouldn't be enough. If Pete asked, he'd give him a witty reply about how he figured that if he was named after the Dog Star, why not go with that?
But if Remus ever asked...Sirius would take a deep breath and silently recall the reasons. He wanted to get closer to Remus, he knew that a werewolf would tolerate another canine better than a stag or a rat, and he'd be able to stay closer. When Remus finally relaxed, it'd be Sirius whose large paws would be gently but firmly pinning him down, not anyone else's. It would be Sirius who Remus would look to when he needed a shoulder to cry on, exhausted from the Change, albeit, it was always black and furry. It'd be Sirius that Remus would find curled up next to him, when he had to get away and hide. Yes, it was to get closer to him, but not just in a physical way.
It was Remus asking him now, the two huddled together, James was off aways, making sure no one got near, Pete had scurried off to help.
"'Cos. I've always wanted to help you, this is the best way I could think of."
Remus was smiling wearily. "Thanks, Padfoot," came the quiet reply.
Sirius didn't reply, he was too busy watching his friend lay his head on his now bony, robed shoulder, his eyes falling shut.
"You're welcome..." he said softly.