Responses
I think he genuinely likes the doctor that is why he's been able to open up and talk so well. I also think the doctor is a good listener despite also being a playboy with a slightly twisted personality. I think the doc realized he liked dojun at the lee family gathering when he felt protective of him and acted on it.
But he does have low self esteem and it's sad he can't or won't speak up for himself so he can say what he likes or doesn't like about the foreplay. Maybe he just needs the doc to stop using his pheromones like that.
He has VERY low self-esteem this is why is in this coercive "relationship" with the doc.