Sunmi guesses exactly the reason for Junho's outings and wants Yunho to rail her right infront of the camera Junho set up to give her son a good fap material.
Bora is extremely bitter and obsessed with the idea of breaking apart Yunho & Yoosun. So, she stalks Yunho throughout the whole summer. One day, the in-laws go on an outing together with Hayul too, she stalks them through the entire day. She feels that she wasted her time doing so as nothing suspicious happened during the whole day, but later at night her fears come true as she clearly sees Yunho and Yoosun fucking passionately. She interrupts them and gives them a good scolding & even threatens to snitch.