
I wrote the spoiler 2-3 months ago bc ppl were complaining and hating on Heiner. So I spoiled the ending. If you really hated the idea of Annette getting back together with Heiner, the main novel ends here. It is ambiguous if they do get back together. It's open ended. It's hopeful and heavily implied Annette is giving Heiner a chance again.
So for those that hate Heiner still, you can stop here.
The side story, though, continues where the main story left off. And they do eventually get back together. They also do the hanky panky, with Heiner revealing his insecurities about the scars and tattoos on his body. Annette reassures him she doesn't care, and they replace the painful first time with something more sweet and tender.

The dad is dumb, but he couldn't direct his anger at the royal family and other ducal family, so he directed it towards the easiest target, Olivia.
I also have to mention, he is actually justified in his anger towards Olivia's mother. Unlike other manhwas, the father got legitimately raped by Olivia's mom. Olivia's mom was coerced and blackmailed to sleep with the Duke by the duke's political enemy. Since he is part of the imperial(?) faction with impeccable reputation, known to he a devoted and loving husband, they targeted his reputation as a faithful husband.
They drugged and knocked him out during a party, and had Olivia's mom sleep with him.

The novel is one of the more interesting novel. Too bad the manhwa sped up the pace. It doesn't skip scenes per se, but they don't put emphasis on the internal dialogue and stuff. I tried reading past what was translated using MTL, but once you get into the Murim arc, it got Google didn't know how to translate the murim terms. I kinda dropped it around when the MC created a female avatar of himself.
This is kinda frustrating that no one, not even the FL, thinks to ask the ML if he likes the princess.