Even when Riku wanted something, he was, above all, protective of those he loved. He wouldn't demand his sister do something that made her feel unsafe. He'd trade his life for the ones he loved without hesitation.
When Corin stopped by to see them, Riku encouraged Namine to go with him - he wanted to continue watch his Beloved dance. He wasn't expecting to be asked himself. "I... certainly, My Lord. I would be honored." And, luckily, Riku had been trained by Sora enough to know how to know whether he was to lead or follow based on how the other escorted him to the floor.
"That is a shame," Belle voiced. "I met you first, out of uniform. That is how I always think of you." And she did. Think of him. "He will recover, thankfully, in time." She had been really scared for her father. "I am the eldest. My only brother is child." And between him and her sister, who she feared might never be independent, she had a certain level of responsibility that was always with her. Except, perhaps, around Conrad.
But she did NOT like that, for Conrad, the war was not over. "I will worry about you. You must take care that you return unharmed."