Facebook Messaging Question!?

[girl]

Okay so I sent someone a message a while ago and it was marked as "seen" with the little check mark. A week later I go back to look at the message and it no longer says that it was "seen"... what does it mean? Neither one of us replied again. Thank you for your help!

BTW- I have messages from a lot longer ago that still have the notification.

[I love him.]

Now you can choose whether or not you want your message to be "seen" or not, perhaps the person has unmarked it, I tend to do that a lot myself.