The others thought that he was stupid, Peter knew. Sirius and Remus made so much effort to hide their relationship from James- not that they were good at it; how could James not see straight through them? -but they never bothered to be careful around Peter.
All the same, as the pair handed each other presents on Christmas day, blushing and flirting subtly in turn, Peter knew. Just like he knew that Sirius had recent scars on his wrists and that sometimes James cried himself to sleep after his mother's death.
But the other Marauders… they didn't know a thing.
