I dont understand the people who are getting angry at Hayoon for all of this. She literally points out that the vast, vast majority of alphas will just toss aside omegas when they get bored of them. Omegas excrete hormones that make alphas want to fuck them, so of course she doesnt think that the sex means anything. Minju is already known as being kind of weird about her, and incredibly possesive, so her confession could just be a way for Minju to monoplize her, whether or not she actually likes her. The more I look at this the more it feels like rape and stockholm syndrome (sorta) that has been made socially acceptable.
For this situation, you shouldnt think as if it was this world, you should think of a world where an entire class of people was famous for randomly toying with people like you, then throwing them away, and a girl from that class that basically demeans your existence confesses to you and treats you well. She can never quite be sure whether the girl likes her because of pheromones and as a toy, or if she actually is in love with another human being.
It also doesnt help that Minju constantly does things without ever asking or telling Hayoon, and then ignores Hayoon when she says she dislikes it, under the pretense of "already knowing she loves her", not exactly what I would call a healthy form of love