No, it's not a common expression. Usually, we would say something like 'You are my son, and that's it' or 'You are my son, end of story' in a more standard way.
It could mean that the person is simply stating a fact that the other is his son and that's all there is to it, like a final statement without further elaboration.
" Dut-in-law " was a popular historical novel written by Angry Banana. It was published on Qidian Chinese website and was loved by readers. The story was about a male protagonist who traveled back in time to become a son-in-law. He only wanted to live an ordinary and stable life. This book can be read or listened to on the Qidian Reading App. I recommend the audio book host, Yaju. His voice is real and can restore the original work. It is more immersive than the TV series. You can also get an experience member if you go to Qidian to listen to books now! You can read authentic books and listen to authentic audio on the Qidian Reading App. The male lead, Ning Yi, was a person who was good at posturing, meticulous, and had a talent for business. The female lead, Su Taner, was a shrewd and capable person with a strong sense of responsibility and a tenacious character.
Her son-in-law, Tan 'er, got pregnant in the end. There were many articles in the search results that mentioned the plot of Su Taner's pregnancy. They described how Ning Yi happily held a grand wedding after discovering that Su Taner was pregnant. Therefore, it could be confirmed that Su Taner was indeed pregnant in the end.
No, I haven't. I'm sorry. There are so many people in the world. It must be really worrying for you. Have you tried to contact the local authorities or put up missing posters?
Well, generally speaking, if it's a religious story related to the concept of Father (God the Father), Son (Jesus) and the Holy Ghost in Christian theology, it's about the Trinity. The Father is seen as the creator, the Son as the savior who came to earth in human form (Jesus), and the Holy Ghost as the spiritual presence that guides believers. But again, this is a very broad overview as there are so many nuances and interpretations within different Christian denominations.