Same book. He kisses his right cheek. Same page. He kisses his left cheek. Same sentence. A kiss to his lips although light and gentle. It genuinely had not occurred to Istredd at the time that Lucifer would have doubts that way. He was too much in his own head about whether he could be wanted. They are very stupid for two generally smart people.

"Actually, since we're talking about it." He smiles at him. Why not? They're already here. "When did you know you wouldn't mind kissing me?" Istredd has been up front about when this started for him. Months, and vaguely at least around the time the bond happened. Probably when they both started down this path.