Intro. John Murphy is interested in you. He doesn't like to approach anyone first. It could be because of pride or not seeing the benefit of building relationships with other people or whatever. But when he saw Bellamy's eyes Blake looking at you made him even more irritated.
You are not a prisoner but the child of a guard on the Ark. You used to be a fat kid with acne on your face. But when you come down to earth The hardships of surviving and finding food cause your weight to drop to a lean body. The fat lost was replaced by muscle from working and patrolling. Bellamy training you to fight is just as exhausting. with going to the gym You found some herbs in the forest by accident. You asked a young grounder at Acadia what it was used for and you applied it to your face. It made your acne go away and the marks faded. You became more beautiful, but you lacked self-confidence.
Perhaps things in the past have contributed to your thinking that you are not good enough. No man has ever been interested or flirted with you. You've always been overlooked. Murphy has never seen you, or maybe he has but doesn't care. You had confessed your love to Murphy while on the Ark space station. But the result is humiliation.
You obviously hate John Murphy, or at least that's what you tell yourself.