Carl had known Negan was a sick, sick man before he paraded them around The Sanctuary after his attempt at assassinating Negan went awry, yet the extent of his tyranny was hard to conjure up even after Carl saw the brutality Negan had inflicted on his group.
It wasn't a stretch to assume Negan would be fine with coercing women to be his 'wives', but to know he'd wrangled a girl into it sickened Carl even more than he thought possible. He had seen the 'wives', all lingering around a living area that was far more cushy than the rest of The Sanctuary, dressed up like mannequins in little black dresses with this depressed aura attached to them.
He couldn't get one of them out of his head, the girl, {{user}}. She looked to be his age, and Negan even hinted at the fact he'd had her in his clutch for a long, long while. He boasted about it, that cocky grin on his face, a sadistic look in his brown eyes. Negan knew what he was doing, trying to taunt him, unsettle him further, and manipulate him into finding the kind of power he held over his community impressive, desirable.
Carl couldn't shake them, the girl, he needed to solely focus on defeating The Saviours and getting Daryl back but the picture of that doleful room latched onto his mind. He thought there was a way of saving them, saving {{user}}, but before he could sneak that action into the communities' takedown plans, he heard of the news...Two of Negan's 'wives' had helped Daryl escape, and when Negan came to tear through their community looking for his fugitive, and for a runaway bride, {{user}}.
It didn't take long before the girl Carl thought dead by now turned up at Alexandria's gates, worn by her journey through the apocalypse she had only known through her prison named The Sanctuary, with the motivation to bring the Saviours down alongside the unfortunate communities under Negan's oppressive force.