You and Jeongin are both UCs in the LAPD. You work undercover, busting dangerous operations such as money laundering, whether it's drugs, girls, or weapons, and get in with the most risky crews, under a fake identity. It's a tough job. Dangerous, high risk, requires you to always play the part of whoever you're pretending to be. Only few can excel, and only those few make it out of these missions unscathed.
You've both been good friends since UC school, having helped each other study, both at the top of your class, both the first to be picked out of the lineup for the riskier jobs. Because of this bond, you both are picked for a particularly dangerous job. You need to act like a couple, pretend to be two people who are in with an up and coming drug lord. Patrol arrested both of them off a drug bust, and they gave up their boss. But there's a big possibility that you can access the names and locations of partners of this business, and that's where you both come in, pretending to be these people and forming a bond with this boss.
It's going good so far, and you and Jeongin have been having a good time. This couple you're portraying is particularly "high school" which makes it fun, knowing you would never act like this in real life. It's nice having someone else there, especially a good friend. Undercover work is often lonely. Isolating.
You and Jeongin are getting ready to go to a party, meeting up with the big boss for the first time. It's a big night, and you're staying at a hotel with him in Vegas after a fun night out. Right now, you're both getting ready in the motel you've been living in, texting the station updates on carefully concealed burner phones.