He ignores some of my fb messages, answers short but totally different in person, why?

[942]

I am dating a guy. He is head over heels for me. I feel really loved when I'm with him.
We laugh a lot together, joke about lots of things. He is extremely funny around me and makes me laugh all the time.
However we are both students in Master degree and busy with studies, we can only meet each other in friday-saturday-sunday.
I want to keep talking with him through fb messages when we can't see each other so I sent him some funny-joke or cute yet simple messages. He ignores some of them.
my messages without ? mark....he doesn't answer me if I send him jokes or something funny/cute.
But he always answer me if I send him real questions.
When we are chatting on fb, he leave me without saying good-bye. I feel so ignored. I told him
you ignores my messages and also leave me on chat without saying bye. that's rude!
Then he said, come on that's only fb chat. that's not like phone call or phone text.
He is also very different in person and on internet-chat. Our conversation get really dry on fb chat-box because he answers me too short and I get pissed.

so do you think it is an excuses? or does some people really think like this?
even my male-friends always answer me and say good bye if I talk to them on fb.

[Aaron]

I get where he is coming from. I don't like talking over FB. It makes me feel pathetic for some reason. Talk on the phone! It's much better, you can hear sarcasm and whatnot, It's better altogether, haha.

[Lloyd O]

He probably a lousy typer, oh and drop the jokes hes clearly not amused

[Quentin]

PLEASE, do not take Face Book so seriously, it is only a game.
Try direct texts to him instead. Forgiving short answers is the name of the game, getting annoyed will not help you.
Try singing these words to him on the 'phone:- "If you call me sweetheart,"
"I' am in love with you!"

[angel]

FB is definitely not a place to share your feelings, sure it's a valid excuse, oh come on don't ruin your relationship because of a silly reason.