He's tired but he can manage the walk. If he can keep up with over towering Akuma on daily basis then he can keep up with her. He just can't walk leisurely right now. Not to mention this was kind of an urgent matter.

The silence helps wonders to calm him down even if he is kind of moody now. He glances in the direction she is facing and then back towards her. He reads body language well and will gesture towards said skeleton.

"That is his brother. His name is Papyrus." At least he remembered his name or he should say he committed it to memory in case he needed to apologize later. Well, he might apologize later. He doesn't really see those words he said being his own even if he would've said them in general were he actually the enemy.