I'm inclined to believe this would be a perfect threesome. Mok-yeon wants Nanjo, Nanjo wants Sunhwa, and Sunwha wants threesome and the drive from Mok-yeon plus the wealth from Nanjo. No one understands better Mok-yeon and Sunhwa that both of them so... Works perfectly from my perspective.
Okay im gonna prepare my heart that they wont end up together… just in case so it wont hurt much