Kaneki walks through the door and sees Tsukiyama smelling the piece of cloth that he gave him(it has his blood on it).

Kaneki: "Uh...what are you...doing?"

Tsukiyama: "Nothing."

He puts the cloth in his pocket.

Kaneki: "No you were definitely doing som-"

Tsukiyama stuffs a snickers candy bar in Kaneki's mouth.

Kaneki then spits it out.

Kaneki: "Ugh... Why did you... do that?"

Tsukiyama: "Because I smell like grapes..."