Honestly, Riku thought that it would be good for Sora to have his cousin near, even if it was just to ask about sex and relationships - his cousin had been involved with a man for a LOT longer than Sora and had more practical advice that even Master Zexion couldn't give.
And Riku would like someone around who had intimate knowledge of navigating two worlds with grace. "Thank you for the dance, My Lord," Riku said with a polite, friendly bow and a smile. "I am sure we will be seeing each other soon."
Belle had no such reservations against smiling, even if her cheeks did turn just a little traitorously pink. "I think I should most like to see her garden. You will have to show me your favorite spot there." Maybe he'd even helped take care of the garden, as a child.