Secretly With My Brother's Friend

Ji-Soo, who was strangely rejected by men, starts dating Tae-Joon, her brother's friend, but hides this fact from her brother Ji-Sung. Ji-Sung, Ji-Soo, and Tae-Joon end up drinking together at home. The two, who have been dating for a month, feel hot just by making eye contact, and eventually, even in the house with Ji-Sung, they are busy exploring each other. Will their risky sex be able to stay hidden until the very end?(Source: Ridibooks, translated)