I took a chance on someone I loved. And he threw that chance back in my face more than once, put the magic before me, the need for revenge greater even than his love. But ultimately I still see that good that first drew me to him.
So maybe your friend made a mistake, did something awful. Maybe he will again. You need to decide if he matters enough for you to stay by his side. Not agree with his actions of course but simply decide if its worth it