Well she'd said she was coming. She wasn't sure that she'd get to see Sora if she arrived any other way. For her part, she considered it rude the way his boyfriend hoarded him away during the holidays like this.
Sora perched on the couch arm. "Is this okay with you? For me to spend today with her." he asked right out. "I know we didn't have any real plans or anything." Meaning if they did, he would have cut the time down to an hour or two only. Technically, he didn't need to ask Riku, as Riku didn't make Sora's decisions for him. He wasn't going to tell Kairi no completely either, even if Riku said so. But he didn't want Riku to think he didn't care about what he thought.
In the meantime, Kairi didn't really move from where she was. She really didn't want to make herself comfortable.