love is an illusion, u probably read it already tho - since it's the most popular omegaverse
Idk if it would be really considered hiding bc the Alpha basically hid it from him but https://www.mangago.me/read-manga/hypnosis_mic_answer_doujinshi/
If you can ignore the fact it's a doujinshi it's a solid oneshot
Love Shuttle
Omega Complex
The Rogue Prince Is Secretly an Omega
Living as an extra in a BL Omegaverse Novel
Dear Benjamin
Turning (maybe?)
THANK YOU FEESHYWIIE, LIN, 若汐, AND CRINGECRINGECRINGE FOR THE RECOMMENDATIONS!! I'll enjoy reading them!
Dear, Benjamin
please recommend me something where the guy is hiding the fact that he's an omega