Yeah it does take two people to make a relationship work.
I'm pretty sure they texted during his absence when he shared being sick.
MC doesn't seem ready to accept his situation entirely yet. Even if asked directly I don't think he'll be honest about.
So may come across more distance than usual, his friend probably senses there's something off so feels frustrated.
It doesn't justify his actions though it is understandable.
i can now sorta feel for the friend when my best friend didn't tell me she'd been dating and only revealing it when she's engaged. however the "friend"'s reaction is totally uncalled for. i just took the news of my friend's engagement in stride and had been caught up with helping for the ceremony to feel anything negative haha. anyways can't wait to see the friend's reaction when he learns who Baekwoo's partner is
uhhh what's with baekwoo's friend?? suddenly lashing out acting like he knows everything about baekwo, it looks like he's just jealous that popular girl liked baekwoo instead of him and when the girl and the friend started to flirt, friend acts like he didnt do anything wrong to baekwoo like???