Why Sul always grab Jung's hand?

Do you guys feel nostalgic when Sul grab Jung's hand always at every "tense" scene? Like he would go first, try to kiss her or hug her, then realize he stop because he notice Sul feeling uncomfortable. Then, almost EVERYTIME, Sul would grab his hand and do something random. Do you guys know what this mean, any symbol? any hidden meaning behind this nostalgic scene?

I think at first,Sul, who overthinks anything, feels that there is still a space between her and jung.
she feels awakward sometimes and doesnt know how to act towards jung.
thats why she sometimes has a late response to jung. but then she always grabs jung's hand like she doesnt want
jung to leave her, I think its because she loves jung deep inside her heart. (sorry for my bad english)

I think Sul still feels unconfortable when he tries to hug or kiss her, I don't know why, because they have been dating for a few months now, but she doesn't want him to think she is pushing him away

It is explained later in the serie =p

I'm not helping, I know ^^



now you are dying of curiosity