For what reason is a guy mean to you?

Drop him from your radar. He is insulting you to to damage your self confidence and make himself feel better. Any time spent with him is time wasted. There are a billions of people in the world and you should surround yourself with people who have something positive to add instead of someone who is polluting your energy. The next time he insults you, calmly say to him that you don't need crap like him in your life and he should lose your number. and then Walk Away.