it's not that i disagree with you that a teen is hitting on a toddler literally but i have a hard time believing that he has any clue what it means to marry or whether his actions are inappropriate but for me, he's a child and he's ignorant to the world. literally grew up abused and imprisoned so like.... i think he might be like 12 but that's hardly old enough for him to be a predator. especially when he neither abuses her nor hides his affection for her. the way i interpreted it is that he is confused bc he's never received warmth from his own family and so he thinks on top of being emperor, marrying her means he will have a family for life. also, intellectually she's a lot older than him and she's his savior so i don't think his attachment to her is odd nor romantic. it never even occurred to me it was creepy after the first proposal before he explained why he was asking. of all the isekais with somewhat icky or problematic relationships between adults and children, i see this as one of the less problematic ones. she's so fucking old and doesn't behave like a child even a little bit. but maybe i'm alone in this. plus that kid is extremely pitiful to me. and i think FL too.
He is pitiful and I do think his abuse was sad yes but I don’t see him as naive. He has received the education of a prince. Can’t expect such a person to be clueless of what he is doing. Also she may act mature and we as readers know she isn’t 5 but he doesn’t. He doesn’t need to have malicious intentions for this to be disturbing in my opinion. But there is also the fact that no one would propose to a toddler with pure intentions either. He can receive warmth, love and protection from her as a younger sister too that doesn’t need to involve marriage. But you’re welcome to your opinion and yes I have seen worse with isekai’s stories.
Yea the 1st prince proposing to her doesn’t get any less disturbing and disgusting no matter how many times he does it.