Home. Whether Hayun knows it or not, Yohan knows exactly where that is. And exactly how long it takes to get there by car at any given time of day. And also... the big lie: that Hayun lives there utterly alone.

While Hayun says he doesn't need to come, it's obvious in the boy's tone that he wants Yohan to be there with him. So, Yohan slips an earbud in so they can continue talking en route. Does he mention that he's going to come over? No. It should be obvious that that's his plan. Outside his office, he waves to Siwoo and points to Hayun's contact information in his phone. Yes, please, take him there.

"There's very little I need to do. Let me come over because I want to." Because he wants to be there for Hayun.