I was wondering why that is if you are friends with them it will say seen or they could mark it as unread
Most Helpful Guy
It's a privacy issue. You can't see if they've read it or not and they are often not even alerted to a new message since they're not "following" you. For that matter, it could be a result of the fact that you are not "following" them since you two are not friends.
Either way, when messaging girls on Facebook , it's better to have them on your friend's list.0