I don't think they had sex. More likely Haegyung was just exhausted from carrying Kiwoon's heavy ass to bed. But because Jiwoon was so drunk he only remembers flashes of what happened and got the wrong idea lol. Haesyung would have mentioned something by now if they had slept together
do you reckon blue-hair just had a wet dream or smthn? or he pulled haegyung down and thats why he was flustered?