The plot twist is that there's only one daughter who's desperate for both siblings and romance, so she created an imaginary sister who also wants to do her. The mother is disturbed, but also afraid of how her daughter will react if she points out that it's all a hallucination, so she pretends to be okay with the relationship.
Brooooo… That’s though but I also think the little sister would do that cuz she the one fell-inlove in the first place. And it’s sad
more twincest ! Yay !
"I don't know how to start a kiss" facepalms I always finds these kind of lines stupid. It's not rocket science to dock two pair of lips together. -.-
Don't underestimate the (lack of) power of a bottom