Well since some ppl are just into watching other two it's also a type of threesome although here it's just that he couldn't participate
but that's just voyeurism not threesome, threesome is where all 3 participants are in the act together
But only few know that term dude (￣∇￣") so calling that threesome is generally normal
I'm pretty sure it was even mentioned in the chapters that the ex is into voyeurism and the term voyeurism was even thrown around
so saying only few knew what voyeurism means (in this day and age and in this godforsaken site) either wasn't really reading the webtoon or concerningly a younger audience is reading this webtoon (hopefully not)
I'm just technically saying what happened wasn't threesome but voyeurism
also yes I'm painfully self aware I'm this nerd emoji meme "
I was confused what threesome you guys were talking about when I realized what it was I was like "Wait... that was threesome??" cause I don't considered it as threesome cause both lim and goo didn't gave rat ass to kim (as he should be treated)
but everyone do have a personal understanding what a threesome is //shrugs//