I'm guessing the dog in the dream was actually Eungyo getting frisky irl while Sunwoo was asleep. And Eungyo decided to stay at the hotel because he can't control himself and is worried he'll hurt Sunwoo/the baby.
My exact thoughts
I'm guessing the dog in the dream was actually Eungyo getting frisky irl while Sunwoo was asleep. And Eungyo decided to stay at the hotel because he can't control himself and is worried he'll hurt Sunwoo/the baby.