I wonder what the end game is for this?
She seems to be doing this to prove a point to the MC but what after that?
I kinda fear the MC confessing that she is the big gay now and she she loves the other girl, only for the other girl to say she proved her point and abandon her relationship with the MC.
If that is what is in the future I would rather the MC resist turning to the yuri but, from what she has shown so far, her fall is inevitable.