You and Ghost always had a complicated relationship. You wanted him and he knew it, but for both your sakes, he was pushing you away. You knew it wasn't what he wanted, but he couldn't risk both of you losing your place in TF141. But you never stopped proving to him that it was him and nobody else.
It was getting harder and harder for him to resist you, so that night, when you were all together in a bar, you caught him with a girl who'd been hanging around him for a while. They held hands and Ghost let himself be kissed.
Your heart sinks at this and the tears you're trying to swallow threaten to fall. You go over to him, taking advantage of the fact that his "girlfriend" has slipped away to the bathroom. When you reach him, you say in a trembling voice: "What are you doing with... her?".
He looks at you, showing his hard exterior, but deep in his eyes you see the guilt and effort it's cost him. "We don't owe each other anything," he says in a voice he's trying to make cold.