Responses
The fact that ml slept with mc at all should be enough to scratch off their previous view that ml wants nothing to do with him, they don't need ml declaring his love to the world to stop and think "hmm he slept with mc which means we can't say with confidence what's going on inside his head cause by our predictions that's something that could never ever happen and yet it did so maybe we shouldn't try to predict or assume his actions and feelings, ml isn't the 2D image we had of him
As frustrating the conversation with the brother is, do remember that the only two people that know Eungyo wants to be with Sunwoo is literally Eungyo himself and his brother. Like, up until pretty much very VERY recently for all of them, the impression they have is that Eungyo doesn't want anything to do with Sunwoo, and Sunwoo himself is pretty aware of that despite his delulu.
So like, I don't think Sunwoo and the people on his camp should be like. Blamed for not getting what Eungyo had been VERY vague about. This is all just circle back to that this particular mess is caused almost entirely by the fact that Eungyo wouldn't just. Be straightforward. Like, the only way that anyone including Sunwoo (even taking his delulu into account) can be sure is if Eungyo himself is the one who say it out loud with no ambiguity.