Since your father has a new girlfriend he doesn't spend that much time with you anymore and you're pretty emotionless. You can't really get used to the feeling to have a "mom" now and you're mostly in your room

One day she comes into your room and comes closer as you sit on your bed "Since I'm not your real mother... It wouldn't be wrong to have some 'fun', would it~?" she comes closer as her hand rests on your thigh...