Another theme might be self - improvement. The female lead may need to grow and change in order to fit into the billionaire's world, which could involve learning about business, etiquette, etc. Also, the theme of redemption could be there. Maybe the billionaire has some past issues or a cold heart that the female lead helps him to overcome.
I'm not sure exactly as I haven't read it. But from the title, it might be about a character who somehow manages to get a billionaire to be her husband.
I'm sorry I haven't read this novel specifically. But generally, in such a novel, there might be a plot where the female lead is quite bold and manages to 'snatch' a billionaire for a husband. It could involve elements like a rags - to - riches story for the female lead, or perhaps she uses her wits and charm to win over the rich man.
One possible theme is deception. The husband is living a double life, which means he is deceiving his wife and probably others around him.
There were a few novels that he had snatched from her that he could recommend. These included "The Snatched Bride" and "The Snatched Bride: The Great Liao Princess Consort." These novels told the story of the female protagonist being forced to become a husband, involving the hatred of the country and complicated emotional entanglements. However, the specific plot and content needed to be further read to understand.
You can try Goodreads. Although it's mainly a platform for book reviews and recommendations, sometimes users share links to free versions of novels. Additionally, some independent authors may post their works for free on their personal blogs or websites. So, it's worth doing a Google search with the name of the novel and 'free read' to see if any such sources pop up.
The plot of "Miss Loser Is Going Against the Heavens" was like a female lead who had been snatched away by her husband. Not only did she have the skills of a peerless thief, but she was also betrothed to a eunuch's prince. It seemed tragic, but she was able to defy the heavens and change her fate, becoming a powerful female character. I suggest that you try reading this novel. I hope you like this fairy's recommendation. Muah ~
Love is likely a major theme. Despite the secrecy, there must be some form of love between the billionaire and his wife.
Love and attraction could be a major theme. The idea of the female lead being drawn to the billionaire daddy.
One possible theme could be identity. The heiress is likely to struggle with who she really is when living two such different lives.
Social differences could be a major theme. The billionaire is in a different social stratum compared to the accidental bride, and the story may explore how they bridge that gap. Also, family drama might be present. Their families could have different reactions to the accidental marriage, which adds to the story's complexity.