Deauthorizing an Android Youtube app from casting?

Somehow, my neighbor who has an Android phone and shares the same wifi network as I do, can load up his Youtube app and choose my Tivo to cast to. He apparently didn't need to do any kind of authorization, like I had to do with my iOS phone's Youtube app.



Whats the deal with that? Does it really need authorization, and maybe he came over and my roommate let him in to authorize it while I was away at work? Does the Android app not need authorization/pairing? How can I shut it down?