How to block certain casting devices?

[UknowmeimGui]

So I got a Google Home Mini, and I've noticed that Spotify on my MBP will randomly start casting to it without me having selected that option. This is annoying because when I'm trying to listen to music on my laptop, it'll actually start blaring in the kitchen where I keep the Google Mini. I'm not even sure how this happened, as I've never connected to that device using my MBP, nor are they even on the same wifi network... To prevent this I want to blacklist or block the google mini device from my Spotify account or whatever. Is this possible?