On an early morning, Kwangsoo bought some breakfast and a cup of Americano and waited patiently at Jihyo's house.

Kwangsoo: Noona!! Quickly!!!! We're gonna be late to filming if you don't hurry!!!

Jihyo: Alright alright, just wait, let me freshen up first

Kwangsoo: Noona you better do more make up today, I heard Yuri will be the guest!!

Jihyo: Why? Am I not pretty enough for you? Am I too old??

Kwangsoo: No of course not Noona, you know you'll always be the most beautiful to me

Jihyo: Like I'm gonna believe that, look at you, so excited already knowing Yuri is the guest

At filming, Kwangsoo Yuri Jong Kook and SukJin are in one team, while Jae Suk HaHa Gary and Jihyo are in another team.
Although she knows Kwangsoo is loyal to her, she can't help but feel insecure as even she herself felt old next to the lovely young idol. Their team was in high spirits throughout the day and worked closely together, they were in the lead while Jihyo's team was continuously losing. She knew it was for the show, but she can't help but feel a pang of jealousy when Kwangsoo played the peppero game with Yuri. Kwangsoo looked at Jihyo with his puppy eyes hoping for her understanding, but overwhelmed with jealousy, Jihyo simply shot him a glare and looked away. Kwangsoo knew he was in trouble. In Jihyo's team, Monday Couple was of course the representative for the peppero game. Gary used his overly sweet words to joke and tease Jihyo, whereas Jihyo who usually only laughed at them or ignored them, responded to Gary as revenge to Kwangsoo. At the peppero game, as Jihyo and Gary got closer, Gary was about to bite off the peppero stick for it to be measured, but Jihyo held his face to stop him, and leaned forward to let their lips touch slightly before breaking away immediately. Everyone including Gary and Kwangsoo were shocked at Jihyo's actions. They could tell something was going on between Jihyo and Kwangsoo but all they could do was to try and calm Jihyo down. Kwangsoo couldn't believe her, he couldn't understand, all he did was play the games, why would Jihyo do this? He was angry at Jihyo for getting overly jealous over nothing. With an angry mind, he got even closer to Yuri throughout the day while Jihyo and Gary did the same. Both Kwangsoo and Jihyo were uncomfortable with it, but neither of them were willing to back down as the argument slowly became a greater and greater fight. Jihyo was insecure at first, but stubbornly thought Kwangsoo actually likes Yuri as more than a fan. Whereas Kwangsoo was angry at his Noona for not understanding and getting jealous over nothing, he thought she didn't trust him. 
That night, after filming, they all went out for dinner, but Kwangsoo and Jihyo didn't say a word. The Running Man knew their situation was dangerous, so neither of them dared to bring up the couple's issues. 
As they left, Jihyo asked Gary to drive her home as she came in Kwangsoo's car, but Kwangsoo interrupted and pulled Jihyo into his car. Jihyo remained silent through the journey until she realized Kwangsoo wasn't driving her home but going somewhere else instead. 

Jihyo: Where are you taking me? This isn't the way home! 

Kwangsoo: This is the way to my home, isn't my home supposed to be your home as well? Or should I just take you to Gary hyung's home 

Jihyo: Lee Kwangsoo! Don't tell me you're jealous of me and Gary after how you had a lovey dovey day with your Yuri 

Kwangsoo: My Yuri?? Noona, what has gotten into your mind?? Are you insane? Since this morning I've been telling you there is nothing between me and her! 

Jihyo: It doesn't seem that way to me, why did you do the peppero kiss with her then? 

Kwangsoo: That was just the game! I've always understood when you and Gary Hyung were acting all lovingly, so why can't you understand me? 

Jihyo: You knew I wasn't happy with it!! But you still went on, why couldn't you get another team member to do it? 

Kwangsoo: It's just a game!

Jihyo: You wanted to kiss her didn't you 

Kwangsoo: Noona you're the one who actually kissed Gary hyung you know, are you sure it wasn't you who wanted to kiss someone else? 

Jihyo: What choice do I have? I'm too old for everyone, at least Gary would still look at me, unlike you! 

Kwangsoo: What? Unlike me? What do you take me for??

Jihyo: Don't tell me you think I'm beautiful when you've been blushing at Yuri and flirting with her all day! 

Kwangsoo: Noona, I've just been treating her just like how I treat any other female guest. Why is it that you're okay with everyone else but not Yuri??

Jihyo: Because I know you like her!

Kwangsoo: I'm just a fan, I admire her but I don't love her, you out of everyone should know that the best!

Jihyo: Well how would I know if you'd change?

Kwangsoo: Why would I change when I've spent half my life trying to make sure you're safe Noona, why would I love someone else when you're the one who's perfect for me? 

Jihyo: I don't know, maybe I'm too old for you? Maybe I'm not as young and fresh anymore?? 

Kwangsoo: How many times have I told you already, are you that old that you can't even understand what I'm saying? How many times more do I still have to repeat myself??

Jihyo: What...?

Kwangsoo: Noona...

Jihyo: Are you saying I'm getting old and annoying...? You're finally admitting it aren't you... I thought I was just being insecure... But looks like it's true...

Kwangsoo: No... Noona that's not what I meant... I was just angry and speaking too fast...

Jihyo: It's alright Kwangsoo, I finally know how you really feel...

Kwangsoo: It's not like that Noona... Please... 

Jihyo: I don't want to hear anymore... I thought this was just a stupid fight over nothing... But I guess it's more than that...

Kwangsoo: Noona... Jihyo Noona... Please... You know how much I love you...

Jihyo: Enough Kwangsoo... 

Kwangsoo: Jihyo-ah... You'll always be my baby... Please don't be hurt by what I said... I didn't mean it... You will always be the only one in my heart... I'm sorry my angel...

Jihyo: It's too late... 

Kwangsoo: Noona...

Both flooded in tears, Jihyo got off Kwangsoo's car and hailed a taxi to get home. Kwangsoo knew he hurt her bad with his stupid comment, he was full of regret to why he spoke carelessly. He knew it wouldn't be easy, but he would never give up until he got Jihyo's forgiveness.