Nanjo was wearing a tank top when he found Mokyeon who fell on his own in front of his car and brought him to the hospital, Mokyeon spent the night there and got discharged the day after. The next day after he went home, changed and slept he's wearing a dress shirt and he brought Mok home. I don't see anything weird or wrong with the sequence of events. The scenes where he's wearing a tank top are flashbacks to the night before. Nanjo is taking responsibility for Mokyeon bc evidently he cares, he wanted to leave before Mokyeon finally admitted his own role in what happened without blaming Sunwha or thinking Nanjo was unfair and genuinely apologized, that was the missing piece Nanjo was waiting rather than all the sorrys. The dream theory makes no sense tbh and never did.
this def a dream because how tf nanjo changed his shirt that quick, why is it morning already, why is nanjo so nice suddenly, why is mokyeon shorter and cuter, why is nanjo so receptive to his explanation when he was so eager to drop mokyeon and wash his hands from him like im mad confused