DEV simply wanted to say that at one point in the game a Li (ex: Izzi) will ask you if you want to participate in a 5-person sex with other guys or with the owner of the restaurant she works at and you say no, but She still tells you that she will do it, even without you. In other words, you as MC allowed this to happen, and also depending on the LI, before starting something with you, she says she wants to be with you but she's going to have sex with other guys and then it's up to you to decide if you want that for yourself or not, if No, he breaks up with her and there is no more route with this character.
Why do you think DEV created 20 characters that you can interact with and stay with, one was for gender diversity and such and the other for you to choose who you want or not in your character's life, then everyone is happy.