Why is there an option to follow someone?

[abraXus]

first of all, you have to be at least 18 to make public posts

and on facebook, when you send someone a friend request, you automatically start "following" their PUBLIC posts, but cannot see their "friends only" posts until they approve your friend request

so if that person does not make any public posts, then you wont see anything they post in your news feed

or, if they are under 18, you wont see anything by sending them a friend request, because they cannot make public posts in the first place

to answer your question, your only option is to unfollow them after sending them the request