Butt.

Look, this felt pretty weird for Rin too, ok? Talking to a dog telepathically, a dog that just happened to be his best friend who didn't even remember being his best friend-- Couldn't they both just accept this was weird and get it over with? Sousuke was just lucky the powers that be were merciful enough to give him this form in the first place, as far as Rin was concerned. Awkward, yes. Different, absolutely. But helpful, and, most importantly, sentient.

... Hn. Though part of him did have to wonder how this would have played out if he could just carry Sousuke around and avoid having to look at those flat expressions of his. Oh, and avoid being thumped in the legs too, which Sousuke clearly felt no guilt towards.

"Oy," he grumbled once Sousuke passed by, tail in the air, ears pricked and alert. Should've flicked his ear again for that one. Oh, up the stairs he went, huh. He stayed at the bottom in the meantime, not wanting to interfere. Had to give Mr. Grumpy some space to work and all that. At least until he heard him speak again and perked up in interest, climbing the first couple steps to give himself a better look. Wow. He did it. He actually did it!

"Heh. That's the way you gotta do it, Sousuke!" His little plan worked! "Now can you figure out which direction she went?"