Because if you love him, then you would be trying so hard to make the person you love turn into you, do not go in the direction of someone else. Trying so hard that it feels you are almost insane. That sometimes, there are times when you want to run into the arms of someone else.
You're tired of maintaining everything, when it slowly but surely destroyed everything in front of you without you knowing why. And when you go into the arms of someone else, you might not know everything just after and messing around.
But when you fail to keep your love and your love chose to walk away, you will be watching from a far, cursing loudly down in your heart . Upset and anger is in you.
But if your love tell you that he wants someone else, you're just going to nod, silently wipe the tears and tell him how lucky you were to have him once.