So… can anyone tell me what is happening to Jeonsu? Was he just… sore? Or there’s so...

I think he's just sore esp since it's his first time.
Kinda suprising that they showed that tho ^_^

Well, it did take them like 85 chapters to have sex. They didn’t just jump into penetration and even stopped when it was clear it wasn’t going to happen. It’s been pretty realistic so far, so I’m glad it’s sticking to it.