First off, thank you for you very sweet and kind words! I am so glad you love memoir and have enjoyed it so far :) As for your question, there are a few things I need to re establish so you can understand the answer to it.

In this world, status in class and in subgender is EVERYTHING. Alphas (and betas too but not as strongly) hold all the power, particularly upper class alphas. I have shown this power dynamic by making servants/lower class individuals mainly betas and omegas, while alphas being the ones in position of power. I also have purposefully omitted male omegas to stress just how rare they are. There is a very rigid and strict hierarchy when it comes to class/subgender.

With that said, in this society where your rank and subgender are everything, Beomgyu is an anomaly. A lower class male omega with no father, who is also a servant and a protected member of the royal House of Choi…it is unheard of. It’s stated early on that his birth/existence caused an uproar, many claiming that he is a nuisance to the royal family and is undeserving of their protection. For a long time, Beomgyu was told the only reason he was even allowed to exist was because Queen Eunyoung and his mother’s bond as queen and handmaiden. If it weren’t for that, he would have been sold and bid off to some place else. (All of this discussed in the early chapters btw if u want to go back reread!!)

Anyways, flash forward to later in the story where Beomgyu finds out the truth. His mother explains more of the situation to him. Hayoon died before Beomgyu was born and due to this, his mother, the king, the queen, and Junsu, were all hoping that he would be born an alpha. Because an alpha would have the power to reclaim his father’s position and inheritance. If the world found out the great General Hayoon had an alpha son, this would be highly celebrated. But Beomgyu was born an omega and all hope was lost because male omegas have no power whatsoever. This is why all of them hid the truth behind Beomgyu’s birth and his real status in order to protect him. Junsu stresses this to Beomgyu later on, telling him “Your father being as powerful as he was, had enemies. It is a reason your mother wished for an alpha, for someone who could claim his name and have the societal strength to fight for it." … "If people were to find out that the son of the great General Hayoon was not only alive but a male omega…you’d be in danger, Beomgyu.”

Now with all that being said, the answer to your question is this: Beomgyu purposefully conceals the truth behind his existence not only to protect himself, but because there is no way he would ever be able to reclaim his father’s name and have the societal support for that. He understands his role in the world and how he is viewed, he understands that there is no point in revealing the truth because who would believe or support him? (Important to note here that Beomgyu’s tendency to lose hope and have very little confidence/trust in himself strongly reinforces his belief that his real identity doesn’t matter). Furthermore, there is also no way for him to actually prove that he is Hayoon’s son unless his mother, Junsu, or the queen come out support it. And the chances of that are very unlikely considering they all hid it from him his entire life.

I will definitely explore Beomgyu’s thoughts and conflicts with his true identity now that him and Yeonjun are together. It will play a very important and prevalent part in these upcoming chapters! So there is a lot more to be discussed about that, especially regarding how this information may or may not make him worthy enough to be with Yeonjun. Anyways, I hope this clears up some confusion for you :)