Peter was worried, because he had always harboured the secret insecurity that someday his friends would decide that they were much cooler than he was and be done with him, and he would turn into one of the people they played tricks on. He knew he wasn't handsome, or charming like James and Sirius and he certainly wasn't as clever as Remus. He was just Peter. Average Peter.
He was already up in the dorms, sighing as he tried to work his way through a bit of homework. He actually did fairly well in his classes, but he did have to work at it, and he was scratching away in his messy writing, crossing things out as he went.
When the door swung open, he glanced up, and mustered up a little bit of a smile for Sirius, although it wasn't much of one. "Hey," he said, dropping his quill and wiping an ink stain off on the side of his trousers. "What's going on?"