Woonim is having a hard time because every time that he'd asked for an explanation before, he'd been brushed off; he thinks that this time won't be any different. And to add insult to injury suk-yun completely dismissed any personal connection between the two of them in front of someone with already questionable behaviour, who suk-yun obviously knows well. And would you like being in a relationship where you were always on a time limit?
Ah okay I see your reasoning.
But in my opinion for that dating someone with a time limit, if they explain to me why, I would understand and try my best to keep up with the time limit. I'd try to communicate with them on why they work so much and try to make the hours less for them of possible.
I'm going to keep what I said in the comment, but what I should've really said was they need to talk it out more. Understand each others point view.
Honestly tho, Woo-in is an ass and sun hyuk deserves better. Woo in isnt giving him the chance to speak and open up. Honestly, a fucking asshole