There is a Mermaid in the Basement of the Mansion

Han Kyungseo, a lame, recessive Omega who devoured his husband, received a marriage proposal from a chaebol Alpha. If he gave birth to the offspring of the monster trapped in the mansion's water tank, anything could be given in return. Finally, after the wedding, he found himself facing Parang, a mermaid with piercing blue eyes, within the black water tank of a secret mansion. Kyungseo realized that the humming Parang hummed was the same humming he often heard in his dreams, while Parang, in turn, discovered that Kyungseo, a mere human, could understand him. [I won't kill you, not yet.] [It would feel strange to devour someone you can talk to.] From fear to curiosity, from curiosity to a...