Why did yohan said no we're not dating??!! frustrating （￣へ￣）

I believe it's bcs when they finally started communicating again, or so we thought... yohan said he'd do anything to be with him even if they just sex partners so they never specifically said "hey let's date, you're my boyfriend" and yohan being so dumbfounded lol he just assumed that they really are sex partners and all he wants is to satisfy jihyun and make him happy