
I think what Sanho meant by "it hurts" is probably him feeling uncomfortable. I mean it's his first time having sex, of course he'll find the sensation weird. Anal sex shouldn't be painful, but it's not 'easy' to have a foreign object invading you down there either. I'm glad
Dongha wasn't rough with Sanho.

Wut? Unless you are very well prepared, or already loosened up from recent intercourse, anal sex is PAINFUL. If someone says it hurts you don't second guess them just because YOU want to nut, you stop. We all agree to overlook stuff like this because it is Yaoi after all, but please don't carry nonsense justifications over into real life. Dongha was rough. It's okay to enjoy it in the story, and I wouldn't be surprised if Sanho later backs up what you said, because once again, Yaoi, but going on what we've seen thus far, he was rough to the point of rapey.
It'd be a comedy if the new twin falls for him, and I'll love it hahaha
I'd love it if that happened, but isn't he in love with their boss, the girl dating Hajin's ex?
He could still be charmed lol