I think it's implied yujun slept around too. in chapter 35 when he answers his phone, his friend says "another girl? lucky bastard"
I don't think so.. the girl might be a friend and even said jiho is coming to reunion.
I don't necessarily mean that specific girl. His friend asking "another one?" shows that yujun has been at the very least spending a lot of time with a lot of different girls. He's definitely a womaniser, whether or not he's been having sex with those girls is open for interpretation. You also need to keep in mind he's 24 now. It's rather likely that in the six years they've been apart, on top of the frequency of his meet ups with differnt girls, that he has slept with someone.
Idk about that, judging by the character he won't have done it, he's too broken because of his first love. He's too broken but at the same he still love jiho. But what jiho did was unacceptable.
Jihos the exact same tho, still loves Yujun so so much yet was able to temporarily fill up his loneliness (and hole) with this random mf. I think there's a high probability that yujoon has also slept around to try and escape his loneliness
Can someone link the raws or at least tell me if ML has dicked down people besides MC in the past, yk i just think it'd suck if MLs only experience was MC while MC was sleeping around while they were apart.