Iki Okure Seijo no Shiawase - Vol. 1 Ch. 1 - The First Step to Happiness

[Grinning_Idiot]

Tbh I can't blame the prince for not wanting to marry her. It'd be one thing if he was the same age or they met when they were both in their 20s, but he was like 12 (almost 13) when they met, and she was presumably an adult, or at least old enough to get married (she said her previous engagement was cancelled the day before the wedding). That's a pretty big age gap for a 12 year old. Still, he didn't have to be so rude about it.

Also I could have done without her meeting and raising the demon guy as a child.