From a guys perspective, I think this was the first time she was flirting with a man. chances are, there was no contact before that point, which is so innocent and nice. But the idiot new-husband didn't get it... and even if she meant, why would you slap? I'm sorry, if that is not a sign from Allah (swt) to the bride or the bride's party about the behaviour and character of this man... I don't know what is?