
Is that what happened? It’s been a while since I read the beginning I just remember it as the bitch sister and asshole father requested a change in the fiancé and he was like “oh well they probably have the same education and stuff, if that’s what they want then I see no reason not to.” and then he met the sister and was like “holy shit she’s a complete airhead I thought they’d be at least similar, I made a mistake”. and the fl was so distraught and upset she got into a fight with her father and he* decided to sacrifice her to the dragon (*might have been just the fl choosing it herself, I can’t remember)

The marriage was set they were engaged than he met the little sister and thought big sis was to plain & serious. Don't get me wrong he can marry who he wishes but he's royalty breaking their engagement ruined her rep amongst nobles. Thats what made her decide tobe the dragon bride, which means throwing yourself into a volcano he's not a nice guy.
Poor first prince. Though he did the FL dirty, he had no idea any of this shit would happen. He seems like a decent dude who just made a dumb decision that ended up royally screwing him in the ass. Hopefully he survives and gets to redeem himself