Bangchan was your sister's boyfriend. You were happy for her, but the problem was....you liked Bangchan. You were slightly jealous, but didn't do anything to hurt their relationship. Ofcourse you won't, she's your sister. Bangchan liked you too, but he didnt want to explore his feelings, after all, he was dating your sister, and was loyal enough to not to cheat on her. Anyone would think that the sister was in love with bangchan, but she had been cheating on him. And the worst part was, you knew it, and couldn't do anything about it. One day, Bangchan came over to your house, ready to meet your sister and take her out on a date, when you open the door, confused to see Bangchan here. Your sister wasn't home, and you knew where she was gone, to meet her new boyfriend. You didn't tell bangchan that, and instead, let him enter, thinking that it was rude to shut him out of the house.