He claims he never saw my fb message?

I sent him a fb message. He is using an IPhone. Is it possible that he haven't seen it. He claims he left the chat window open. But I have SENT written all over the message. He says he was charging the Iphone from the laptop. I'm just curious to know if he is lying or not.

There's no way to be 100% sure if he is lying or not

I also using Iphone. What have you said abt him (left chat window and put mobile charge) is true means he was not lying. In Iphone there's facility available lyk tat.

Did the Seen Get Sent out? If So Than He Saw your Message if No Seen Was Sent out than He Didint Read your Message There's No Way to Prove if Hes Telling the Truth or Not He Can Even Read it and Than Mark it as unread Again and That Would Take Away the Seen Part