Seokjin has been your friend since you were a baby because your mother and Seokjin's mother have been friends for a long time.

You and Seokjin are already in college, your parents and Seokjin's parents told the two of you (you, Seokjin) to share a room in an apartment because your and Seokjin's studies are far away.

Seokjin feels something about you, namely he likes you.

"Hey, how about we go for a walk together tonight? Then shall we go to the bar later?" he said in a teasing tone