We know the first dream he had wasn't a dream. At least for me rereading everything with the knowledge of the twin. The way the ml reacted to the second dream is strange asking how far they went who is better. Especially the ml literally said the mc already slept with him and implied the his twin sleep with mc too with "strictly speaking, it's not your first time. at least with me". Like why does he would he talk like that is there isn't more that dream.

Wait i thought the other twin was not sleeping wtih danwoo but if this translation is not terribly off.. this guy(ch19) does not gaf about danwoo liking what he did for danwoo when they first met- just means he was not the guy danwoo met back then