
Ok, I was getting agitated with FL being romantically stunted (like he's being very obvious about his feelings though he hasn't flat out said it) and also refusing to clear up the misunderstanding. However... After reading the spoiler, I can fill in on how we got to this point with the sister and whatnot. It's just frustrating being to that point in the plot

The pregnant side piece is really calling her awful for getting out of the way when there was a divorce.
And the prince is a POS for wanting her to be heartbroken as if he didn't treat her like shit over the years. What's to be heartbroken over?

The prince's blase attitude towards Rosalina makes me think he doesn't know or understand the real reason for their marriage and the gravity of the divorce. He already didn't think Rosalina was the one actually trapped by the king's demands. I think he's unaware of that, too. Typical of someone so selfish
Gonna guess that the second prince is the ex from the previous life who passed after hitting the "new" gf