I'm so glad you see Yuuri as a Slytherin! I definitely agree that that's the house that suits him best. I'm also a Slytherin, which is not something that people usually guess about me right away. There's so much hate for Slytherins in general that I really love having a character that is able to be a total sweetheart and a Slytherin at the same time!
I’m not a Slytherin but I honestly can’t see Yuuri as anything else!