If it were you, how would treat an ex that yea was good and bad to you, not necessarily the best, you made your own mistakes but was very cold to you which eventually led to breaking up with you after trying so hard to mend things. You finally decide to move on and the ex is back from no where, calling you and all, checking up on you. What led to the break up was me saying some words I didn't mean to him when I was mad and due to his own actions. Now the tables have turned.
Would you be mean towards the ex, cordial and friendly or which do you think is the best way to behave to the ex knowing you have already made up your mind not to get back again?