Dangsini Bangsimhan Sai
Hae-min is a beta who avoids alphas due to the scars of a previous relationship. After an impulsive one-night stand with dominant alpha Seong-han, he became an omega. On the advice of his doctor, he searches for a dominant alpha to partner with on a regular basis, and when Seong-han joins the same company as him, he proposes the idea to be sex partners without batting an eye. But then the new team leader is... Jin-tae, Hae-minβs ex-boyfriend who once ditched him for being a beta?! Hae-minβs life is about to take a turn for the worse!
(Source: Bomtoon, translated)