Responses

I think it was right before he left.
He was thinking of Yeon, then smell the cloth, and something stunned him, and he asked for a horse.
Or maybe just when she was bitten by the snake idk.
What i see is that he doesn't know it before he desides to leave. Or maybe he sees how Yeon and Lok Heun resembles each other but cant really believe that they are the same person? So im uncertain.
What's sure is that he didnt know when they last slept together.
i think ML most likely knows by now that lokheun and yeon are the same person bc prior to this chapter, i dont remember seeing him caressing lokheun or sumn like he cared abt him but more of the "u reminded me of my little bro" kinda way ?