Caspian's coronation was very different than the Pevensies' which, at this point, didn't really come as a surprise to Peter. Everything was different in this Narnia.
But there was no Cair Paravel in which to have a grand celebration, and Caspian was adamant that the coronation not take place in the Telmarine castle. So messengers had been sent to the castle to retrieve the crown, and Peter wasn't quite sure how Susan did it, but somehow she managed to procure finery for all of them.
The coronation was held right on the banks of the Great River. Caspian knelt in the sand before Aslan, and Peter placed the heavy golden crown on his bowed head. It was a very different crown than the one Peter himself had worn as High King, and he thought for a moment that he'd very much like for Caspian to have that crown instead.
Caspian looked pale and unsure when he glanced up at Peter, but Peter laughed and helped him to his feet and kissed him on both cheeks, and lead the crowd in the cheer of "Long live King Caspian!" Caspian went quite red in the face, but he smiled back at Peter, and Peter was sure that Caspian was as ready as he could be to be King of Narnia.
Then the celebration began, and there was delicious food for everyone and the wines flowed like the river beside them, thanks to Bacchus. The Dryads steadily fed the bonfires, and the sound of the Fauns' pipes and Dwarfs' drums rang out in the night. All the Narnians drank and feasted and sang and danced, and even though it was very different from their own coronation, Peter agreed with Lucy that it was perfect, and they all had a very good time.
After many hours of drinking and feasting and avoiding the dances as best as he could (for while Peter had many strengths as High King, dancing was definitely not one of them, as his siblings and any of their subjects would tell you), Peter found Caspian sitting by himself, staring at the crowds of Narnians, and looking somewhat overwhelmed.
Peter sat down on the bank next to him, bumping his shoulder companionably against Caspian's. "Wine?" he asked, offering the skin.
Caspian took it with a grateful smile. "Everyone seems to be having a good time," he said after a very large gulp, handing the skin back to Peter.
"They do!" Peter pointed to a group dancing around the nearest bonfire. "Look, even the Wiggles are dancing. I don't think I've ever seen a Marshwiggle that happy before."
Caspian looked over. "And I've never seen a Marshwiggle before at all. Why, are they not happy usually?"
Peter choked on a mouthful of wine. "Not... well, they're not exactly unhappy. Just... Wiggles have a rather different outlook on the world." And he began to tell Caspian, in a rather rambling way, all about Wiggles.
Caspian took the wineskin back from Peter. "I think I might need more of this."