If a Facebook message is marked as 'seen', does that mean someone really clicked on the message?

[Christmas Tree]

My boyfriend sent me a message on Facebook saying he was going to sleep, and the message I sent back hadn't been marked as 'seen.'

Then, a little while later, I had a question for him, so I sent another message for him to see when he woke up. It was instantly marked as 'seen.' I'm not one of those obsessive girlfriends who cares about this stuff, but I know my boyfriend had a friend sleeping over, and I also know he always forgets to shut his computer off. I was wondering if maybe his friend was on his computer and had read my message.
Normally, when it says 'seen' and he doesn't respond right away, I don't care. It happens all the time. But this was something kind of private and I'm worried that his friend is on his computer. I was just wondering if the message can be marked as 'read' even if it wasn't.

[BILL]

Possibly. To be marked as seen you click on the message. It could have been his friend or it could be your boyfriend but he doesn't have the time to respond. This does sound a bit obsessive though. Do you do that to any of your friends when you see that they have seen your message but haven't replied?

[Lexi]

It could be his mom looking at hos facebook,his friend on his facebook tryong to log out or he seen it and hes thinking about the question...i wouldnt say he does have time respond because why would u have time to log on facebook see the message and not respond

[teej]

Adding someone you are in a relationship with to facebook only leads to jealousy and insecurity. If you trust your bf then try not to worry about what is on his account or who sees it. If you want to have a personal conversation do so in a more private way other than the world wide web. Do you have a cell? Text or call him instead. Anytime you send something over the net you cannot guarantee who is going to see it. What if god forbid you break up, then he has all these letters you send him saved on his facebook to use against you. Think before you type and send. Nothing is better than a conversation in person or on the phone.

[Tyme]

Well I can only speak from personal experience. I keep Facebook notifications on, and my iPhone will sound like it received a text and its loud, it wakes me up. I then check my phone opening the message and then I fall back to sleep without responding thinking "I'll just send it once I actually get up", especially if that person doesn't need to know the answer right away.