
Is the prince blind?? How can he abandon such a beautiful and intelligent lady for some whore

First off,the prince is a major asshole. That being said, it seems like he’s been with his gf for a long time, longer than his engagement to Olivia? It seems like the engagement between the Duke and royal family has existed for a long time, but wasn’t solidified until later. If it had been finalized when first proposed, the legitimate daughter would have been locked in as the fiancée whether Olivia came or not, so the timeline is a bit blurry.
The prince doesn’t like the engagement either, he’s just empowered enough to do whatever he wants regardless. He knows that Olivia will never have the political power or social clout to oppose him for anything. Her illegitimate status is a permanent stain that will keep her at his mercy without suffering any social backlash or pressure from the Duke no matter how he treats her.
It clear that he’s obsessed with his trashy soon to be mistress gf, but I guess her family isn’t powerful, wealthy, or influential enough to marry into the royal family or replaced the benefits of an engagement with the duchy.
It’s kind of ironic that for all his arrogance and power, the prince has just as little control over the engagement as Olivia does (he would hate it if someone said that to his face though lol).

They were engaged when they were little, as the empress is not happy about this engagement and is belittling Olivia from the 1st time in front of the prince. So that's how prince got his trashy attitude towards Olivia.
He is the sole heir. And even if olivia is illegitimate, he gets the support he needs from the noble faction. And it’s better than his mistress's support. His missy is delusional, she thinks if olivia was not there she could have gotten the crown Princess seat.
There many kings who's queen come from lower class. But this princy is obsessed with class

The empress is pissy because it is definitely an insult to send your bastard off for a marriage alliance when you have a perfectly marriageable legitimate child. Of course, Olivia’s illegitimate status makes her easy to step on for whatever bs reason literally anyone comes up with, but more than that it’s the fact the Duke and dypucal family don’t give a single shit about her and everyone knows it.
The prince is bitter that he can’t marry the woman he actually loves, but it’s easier to take it out on Olivia than the real cause, his parents. I don’t think he mistreats her specifically because of her status, but her vulnerability and isolation made it easier to do so once he developed the tendency.
I think Ethel knows her situation, but is swept up in the romance and emotions of the relationship. She lashes out at Olivia because she is not only jealous of the position, but irate that it belongs to someone who is “so far below her”. Realistically, she would hate and try to get back at anyone in Olivia’s position though. It’s just that Olivia has no means of defense, so if it were someone else, even Estella, she would have to be more cautious
His friends are getting kinda annoying