"I am used to my dance partners being a little more petite than you so this could go very wrong." With anyone else Istredd would be too stiff and timid, taking more time to relax or never relaxing at all, but with Lucifer it's easy. And he's not self-conscious about the fact he might not be the best at this.

Because of that, he does fairly well. Being comfortable makes a difference and there are only one or two times that Lucifer has to counter a mistake he might make. Luckily there is no tripping although he may have come close once during a backseat leading moment. Istredd chuckles instead of getting annoyed and moves an arm around Lucifer's back.

Do angels even dance typically? I really can't see either of your brothers doing this.

Castiel, maybe, with the right prodding, but he's probably of the stiff variety like Istredd hismelf.