Hear songs on Spotify without others seeing it?

A few weeks ago I sent my playlists to my buddy on Spotify, he then passed the playlists on to his friend and he can now always see which song I'm listening to on his laptop. I don't want that. Can I exhibit this somehow? ☹

Make the list private.

I already have but they follow the playlists and you can't delete followers.

To block?

How does it work?

I don't know, but you can actually do that on any social media platform