Jungkook and Taehyung were rivals, always fighting and bickering.

One day Taehyung made a bet with Jungkook that if he lost he will give you to Jungkook (you're Taehyung's girlfriend) he was so confident he won't lose, even tho you told him to just give up on the bet and not be so irrational.

But... he lost, he lost you to Jungkook.