And that right there is the issue. In a tabletop RPG, you are your character. You decide your characteristics and react based on how you want them to. In a VN you are playing a predefined character. You are allowed to name your character but everything else is already cemented as the character. So, while you personally disagree with a character's choices (and you are most certainly free too), the character will behave in accordance to who he is defined as. You may have ended your relationship in this scenario, but that is not what the defined MC would have done.