This is a very common trope, but the mc isn’t a real character. He is written solely to accomodate the ml’s toxic behavior. If he thought or behaved like a normal person, the crown prince would be unquestionably villainous, but the author is trying to justify the couple. You usually see this in MCs that are bubbly, ditzy, lovestruck, weak, clingy, and seemingly immune to trauma. Authors can get away with a lot as long as the victim doesn’t get too upset in the end. It’s also really common to get a personality flip when the toxic ml is around. Strong and complex characters suddenly become one dimensional doormats whenever the controlling, disrespectful partner is around.
It's sound like this manhwa have novel and you already read it to the end. If not, imo ML's toxic behaviour and ML's family are the one who written solely to show how a person get pressured to almost breaking down due to their spouse and spouse's family status and authority.
Bruh. MC better do something about all those people who controlling his current and future life.
If not, make MC to stop smile or be cold/indifferent to anyone after he keep getting dragged in bullshts. For example, his personality make everyone kinda like him or people getting used to his warm attitude. Then, afrer ML mistake or Imperial family mistake trying to sht on MC, MC stopped smiling and shts. That's would be good revenge tbh.