I do very much agree but in his defense a bit I think this is the first time he has seen his baby in a fitted suit and it was too much to stand but yes he knew how much it meant to him so he should have held it in for once he is quite reckless in doing what he wants but hey at least it makes him more human
that's the thing, he's a human, not an animal who can't hold back when getting horny. Why can't he respect an obvious well-prepared plan, not to mention the amount of money that might be spent for the plan while jaeyoung said himself that sangwoo is a "cheapskate". This is coming from me who laughed when sangwoo was stressful because of bright red padding jacket and lack of black coffee, i even still smiled when jaeyoung seducing sangwoo at dinner table in sidestory 8, but that "are you anxious that i might reject your proposal?" was the first thing that ever pisses me off in this manhwa before everything in sidestory 9 made me want to smack jaeyoung's head

I get that he needs to learn to be less rigid especially if they want to get married, but this day was clearly important to him, so can Jaeyoung really not keep it in his pants??
This is an incredible story, but there is no need to stereotype gay men by portraying them as sex crazed lunatics.