Can I add someone back without them knowing? Yes, and this u003ca href=u0022 will show you exactly how to do it.
Unless a friend screen records the story and sends it to you, or you become a follower, you can’t see a private story. Can I see private stories without adding someone?
Anyway, it is much easier to try to add a person as your Snapchat friend than to try to hack into their account.