Riku was not expecting the Prince to climb into his lap, but he sure liked it! It was a welcome surprise, and he put his hands briefly on the Prince's hips before he was handed the violin. He plucked at it curiously, following the Prince's direction, fascinated with how he was creating his own music while the Prince let his hair down.
Once the Prince reclaimed the violin though, his hands went right back to his hips, holding him in place while he played.
Hayner grinned and snuggled into Roxas's neck, breathing in the wonderful smell of him. "Thank you, My Lord," he murmured, between kisses. "I am very glad that pleased you."