He likes being with her, and it's obvious to one of his best friends when he guest stars on the show.

"Wow, I'm really glad I picked Ji Hyo to be on our team..." Tae Hyun remarked during a filming break when Ji Hyo left to visit the washroom. 

"Why?" Jong Kook asked with a raised eyebrow and a sip of water. 

"I feel like a matchmaker! It's great-"

"What do you think you're talking about?" Jong Kook frowned in an angry whisper.

"Come on, it's so obvious! The two of you are all over each other- ouch!" Tae Hyun scowled as he rubbed his throbbing shoulder, which got tightly slapped by Jong Kook. 

"We are not all over each other! Stop making stuff up-" Jong Kook got cut off awkwardly when Ji Hyo returned, snitching one of his snacks.

"Are you two fighting again? What did I miss?" Ji Hyo asked in an amused tone as she crunched down on stolen food.

The two best friends simultaneously denied any form of conflict, although Tae Hyun only did so out of fear from getting hit again. 

He likes being with her, and she likes being with him. They don't realize that as they crack up at Gary's antics while filming the TruGary show. 

"I think that last line was good- Don't go near the stairs..." Jong Kook remarked, casually praising himself to start a bit of small talk.

"It was so funny just now! I had to turn around when he was asked if he saw a guest, but he said he only saw a VJ-" 

"He said he only saw a VJ- hey I've seen VJs too! There's a VJ here and a VJ there!" Ji Hyo cracked up at his jokes, and they continued to have fun scheming and messing about with Gary.

They take turns interrogating him through their walkie-talkies, laughing their heads off at Gary's nervousness and terrible acting skills. Jong Kook gets so used to Ji Hyo's laughter he can tell from her face exactly when she's about to explode- and stops her with a tender pinch. 

She likes being with him, and his name is the first one that pops up in her mind when they ask her to choose a spy accomplice.

He whines about being the thief again but it's a usel