How do I stop other people from controlling my ps4's youtube from their phones?

Live in the same house as 6 others, we're all on the same wifi network, they keep switching youtube videos and I don't know how to stop them.

I'm logged in on MY youtube account on MY ps4 with MY playstation account, yet they are controlling MY youtube app from THEIR PHONES on THEIR accounts and there doesn't seem to be a way to stop them, they don't have to input a password or anything, as long as we're on the same wifi they can cast whatever the hell they want onto my playstations youtube app, who the fuck thought this would be a good idea?

What about people living in dorms? PLEASE tell me there is a way to stop this.

Atleast on spotify you have to be logged onto the same account on your phone and playstation to switch music, but they are literally switching videos from THEIR youtube accounts on MY youtube account with nothing to prevent them from doing so, no password or anything required, wtf?