Kell takes it upon himself to drag Istredd to dance. He's a fairly competent dancer, and as long as he has better dance partners than random foreign dignitaries or fawning noble ladies, he even enjoys it.

"Don't say no to me," he prefaces his dance request the very moment he approaches Istredd.

He saw Istredd dance with Lucifer, how Istredd seemed more relaxed. They both did. That some of the tension that even he - not being very perceptive with people - had noticed, is gone. It's probably rude to ask, but Kell can't help being curious what changed. Because some things were obvious even to him. He hopes this is what changed.