Rook stopped walking because he wanted Ash's full attention on this. He wanted to be able to see his face and reactions without the distraction of watching where they were going as they walked down the street. Because there were other things he needed to ask and bring up before he stated his intentions.
"Say that this someone could be what you needed—could offer you the things that you lacked in the past but should have had. Would you in return be able to deal with that someone on some nights preferring to not want to be a someone at all? And could you—" for the first time Rook looked nervous and he shifted his weight from one leg to the other, just as he had as the raven, "deal with and be able to understand that it may take time for them to be ready to—" he needed to use human words here, not raven ones and the raven's way of thinking about this "be fully intimate?"
He reached out and carefully ran one clawed finger over Ash's cheek in a gentle caress. "Because if you can, then I'd like the chance to court you. To see if we wouldn't work out as—mates." In that, he only had the raven's words. Lovers was too light of a word for the things that the raven wanted. Needed. "To bond."