Responses
I so agree with you. He should know that he can't have anything with other girls but he personal went and talked to the other girl. It like, he's asking for something. I don't know why the prince didn't get backlashes for CHEATING on the ML but she got backlashes for accidentally "defending" her position. That doesn't make sense. (╯°Д °)╯╧╧

Hmm, I'm glad that they have a flashback chapter to the past (even though I don't normally like those), because I couldn't figure out how the prince; someone who has known her since childhood and had a great relationship with her, could abandon her like that. The string of accidents fit in well with the plot, but as someone who knows her character, never mind the fact that he is her fiance, he should've been able to look at the situation critically and you know... actually SPEAK to his fiancee and ask her what had really happened.
The fact that he had just assumed the worst of his fiancee and childhood friend shows that he didn't actually want to know the truth he just wanted an excuse to abandon her.
So NOPE! That boy failed the vibe check, time to die.