Oh, one of the girls is actually lesbian and not bi--what is the plan there with regard to her relationship with the player character if you don't mind spoiling?
Hi and sorry for the late reply, I missed your comment! They are a various amounts of reasons why people think they are this and that. The lesbian girl may have just tried sexual interactions with females and thinks that she is lesbian. The player also have some... let's say convincing arguments to make her think about it again. (Let's see what reason it will be in the final game, but that are our plans at least.)
Hope that answers your question!