How she feels in general, the way she connects, the way she feels appreciated. Kihyeon wants to take care of everything for her because he believes it's how he'll be the most important person to her, but in doing so Gaon feels like she's losing agency.
He's too preoccupied with his insecurity and the fear he will be abandoned that he actively acts against her interest. In his eyes, he's helping her alleviate the burden of making a wrong decision and hurting people by shifting people's spotlight on him, removing the ultimatum altogether from Gaon's control. In Gaon's eyes, he's replacing and isolating her. And she's not wrong.
Gaon wants herself to be helpful to people, she feels empowered when she witnesses her positive effect on them. And she enjoys reassurance that she's doing good when she's feeling doubt. But Kihyeon is invasive rather than supportive from the sidelines.
Even though he's got all the answers that lead to Gaon's heart, he can't understand them or accept them because in his eyes, they threaten his place in Gaon's heart.

They already said in the synopsis that FL and ml gonna fake date to make goan jealous..which was ml idea ..