it means they would not care if someone was as mean to you as mean as they were to you. sometimes it means they do and its just that they are too insecure to tell the truth and use childish anticks...
well it depends its actually the way he acts to you for example is he is playing around with you stuffs like that that means he like you .hope this works !
Rude, not polite and kind of nasty. It is can also refer to someone who is not generous or is tight with their money. Try looking the word up in a dictionary.