An unpleasant relationship with her sister

Haruna, with her innocent smile and straight eyes, is my girlfriend's older sister! My feelings have completely become a part of Haruna, and this dangerous, unpleasant relationship has begun! I know that such a distorted relationship won't last forever, but I can't lie about my feelings anymore! What will happen to my unpleasant relationship with my girlfriend's sister...! Minato Riku is a popular actress who plays the role of her girlfriend! Of course, I've had sex with her too!