the overall story is cute but that orgy part was not necessary. Like, the story can progress not doing that orgy. They can just be jealous by the thought of the other doing somebody else like, when they saw each other with each other's partner for the night outside that love hotel, they got jealous then go home, then the story continues from that scene when they got to jin's house.
that orgy was not necessary. kinda ruined the story for me