Hereof, can you read a FB message without it being seen?
Switch to Desktop Mode
It also possible to access Facebook Desktop Mode, right on your iPhone or Android Phone and read messages, without being seen by your Contacts. Once you are on Facebook, tap on the AA icon in URL and select Request Desktop Website option in the drop-down menu.
Beside above, why is message delivered but not seen? The recipient can be connected to Facebook, but just not actively looking through their messages to see yours. The recipient might have quickly read your message from the notification or status bar, but the app will not mark it as delivered or seen until the recipient actually opens the conversation with you.
Hereof, do Messenger messages show as read?
Facebook, however, does not. When you read someone's Facebook message, they'll always know — they can see the time or just the date you read the message, depending on when they look back at it themselves. Turns out, there is a way to disable Facebook read receipts, though not technically through Facebook.
Does it show when you read a message on Facebook?
The easiest way to tell whether a message has been read is to log onto Facebook with a web browser. If a friend has read your message, you'll see a miniature version of their profile picture. If they haven't, you'll see a blue icon with a white checkmark indicating the message has been delivered, but not yet read.