Ai think they lit some incense to confuse him but I’m not completely sure. Maybe I’m remembering this from another manga.
well he isn't sober per say, as mentioned the incense when burned acts as an aphrodisiac. however it doesn't make sense that he didn't recognize her. we do know that he has slept with other women before so he probably treated this like any other.
in a sense it was useful to him..? i dont know just to get off, but it's not realistic as you said. the point was to make him more of the antagonist and to illustrate a way to make sure his downfall is imminent.
I don't understand how ch126 could be realistic. Was qianyue drugged as well? How could he forget that he was in an important place and that she was the daughter of an important comrad? Your important comrad is only a few steps away... how could this rationally happen?
Too many of these asian webcomics normalize the concept that as long as the woman is drugged, even if the man is sober he's not going to have any control and will rape her. It makes no sense for the manipulative, conniving qianyue to do something that wouldn't profit him, especially if he's sober and rational.