mal's activites

Hi!! If anyone could help me find the name of this BL, it would be greatly appreciated :) I remember both the MC and ML were sex workers. One time, a woman asked for both the MC and the ML. They were surprised when she said she would them to have sex together while she just watches. They are very against the idea but do it anyways and the lady leaves.. not sure if it was completed but I think it was ongoing

One day, college student Wooseung is deeply moved by an art made by his senior, Sunjin, that he beli...