"Yeah, we can decorate it. Well, parts of it. The lights are put on professionally, usually while we're having a cookie break. You don't drink coffee, do you? Well, there's hot chocolate if you don't." So Sora wouldn't be left out. "We can put stuff on after the lights go on."
Riku hurried down the stairs with Sora and met his parents at the door, putting on their shoes. There were glances at their hands, but thankfully no comments other than Aba asking Sora if he minded putting three in the back of the car.