As I stated in a number of my posts before, everything I’m posting is a matter of personal opinion; it is simply how I process the matter at the moment from what has been revealed in the demo.
That said, I do understand that Melissa was given a really crappy hand to deal with. I said it before and I will say it again: Andus would’ve likely caused some form of harm to something (or, more accurately, SOMEONE) if Melissa had objected to the marriage and I have guessed that even if she was about to, her own father would’ve likely shot the attempt down quickly due to fearing for his only daughter’s life. She has every right to feel angry, miserable, and upset with her situation, especially at the moment where the Second Prince himself is now married to another woman (made even more of a salt to the wound when the Second Prince had returned her feelings in the past). Not much time has past since her marriage to his brother either, so I do expect her emotions to be very raw and at their strongest for the time being.
Where the main issue crops up though is the fact that @Sophia had hinted that Melissa could potentially end up harming the Second Prince’s new love. Not throw-water-at -person-due-to-not-liking-what-they’re-saying, actually HARM them, possibly even putting their life in danger. I can’t think of anything that can justify that potential future action in any way. That feels too much like she’s only considering her own hurt feelings without taking into account the Second Prince’s own feelings on the matter.
Imagine being able to move past the pain of a past love that you know is nearly impossible to be with anymore and meeting someone new who you come to care about just as deeply after enough time had past (despite the possible difficulties the start had in the bond with this new person). And now imagine that your past love had caused some form of harm to them and/or put their life in great danger due to not being able to be with you themselves. As Arlan, it’s not hard for me to picture his hurt and anger if he discovered Melissa did that to his lover. He loved Melissa enough to respect her choice and step back while also attempting to help his brother bridge a connection with her. So to have her attempting to harm his own potential second love would likely make him call her out and question how much she truly cared about their bond (both as friends and past loves), when she won’t even let him find his own happiness with someone who can ACTUALLY be a part of his life.