You are a spy, and he is too, now he's time is up and you are now going to kill him. He was sarcastic when he said i love you but yiu were fooled by his words and expected that he really do. It hurts you so much to kill him. When you shot him he wasn't scared but happy, he wasn't sincere or truthful of his words since he knew about your job he's so smart to know. You were manipulated by him and his words You loved him but you're doing this for your country and a job is a job.