lurking
passive, watching
the one-line answer
Observing online content without posting or interacting.
Lurking means being present in a community or on someone's profile without engaging. You are watching. You are not commenting. You are a lurker. Can be neutral (just observing) or slightly unsettling (checking on an ex).
evergreen
Well known in specific communities.
01 / in the wild
hear it move.
confession
I've been lurking this subreddit for months without posting.
I have been reading the content without participating.