It is rude not to show compassion.
Peter won a competition that his friend Charlie also entered and Charlie is upset about losing.
Peter wants to celebrate his achievement.
Peter buys himself an expensive watch he had been eyeing as a reward for winning.
Peter throws a big party to celebrate his win and invites Charlie.
Peter feels satisfied and Charlie isn't forced to relive his loss.
Charlie feels like Peter is rubbing the win in his face and their friend group see Peter as insensitive.