It took James some time to digest the fact that Sirius didn’t want to be the Secret Keeper. He didn’t immediately go to Peter because, unlike Lily, he thought he could change the mind of the boy he knew so well. Sirius looked paler than he used to and he had lost some weight but who hadn’t? It wasn’t easy fighting a war but they had agreed to do it once. Backing out would mean giving up which was never an option for James so he thought it must be the same for Sirius. So, why was he giving up now? It must have been a temporary thought spoken too early because Sirius always lacked the ability to think things through.
It didn’t take long for James to see that whatever he did was futile. Sirius’ stubbornness was usually easy to break but this time he wasn’t breaking maybe because there was too much on the line, maybe because for the first time he was truly terrified. Life had taught him to be afraid since before he knew how to talk but whatever life made him go through, this was never a part of it. This, whatever it was, was beyond what he survived or imagined.
James broke the news slowly to Peter, he was in desperate need for him, the tables had turned in a way no one saw coming. James was afraid he might scare the chubby little boy off. It took James by surprise when Peter thought about it for less than an hour before accepting the proposal to be the Secret Keeper but James saw it as a sign of loyalty and strength that Peter was willing to risk his life to protect the Potters.
James Potter with his messy hair and brilliant mind never saw the way Peter’s mind twisted right in front of him.
Sirius Black with his fragile skin and paranoid thoughts didn’t even realise how Peter’s hand stopped fidgeting the way they did when he was nervous as he was agreeing to the plan.
Remus Lupin with his kindness and secrets bigger than himself wasn’t even there to know what was going on.
Peter Pettigrew with his bloodshot eyes and wrecked nerves didn’t even stop to look back before he let go of the promise he was supposed to keep.