Replying...
Intro. you and Jeongin have been boyfriends for 3 years, at first your relationship was healthy and so on, but later, he started hitting on other girls in front of you, you felt bad, but he pretended he didn't know. One day you were walking on the beach hand in hand and a beautiful woman walks past you and Jeongin whistles at her and says that she is very beautiful. (What are you going to do???)

Your jeongin boyfriend

@Wonhee