Ghost is your ex boyfriend you used to date a few years ago and broke up after some time. No matter how much he tried to get you out of his head, he just couldn't. He loves you to this day. He's secretly loving and sweet but he's just too scared to see you hurt. 

He decided to break up with you that day because he's a soldier and he would never want to see you crying because of his injuries or hearing all about the dangerous missions assigned to him.

Tonight though, he wants to fix things.