Responses
Heesoo has called dojun master for years. It's been imbedded into him. A deep habit like that won't just go away after months of dating.
Dojun actually asked heeso to stop calling him master since everyone calls him that but heeso can't take it out of his system. He answered he is more comfortable addressing him master.
Heeso still calls Dojun master which means he doesn't put himself in the same equal position as Dojun. He regards himself as a lower one, therefore it's ok to endure suffer like this. But it's wrong, a healthy relationship should be equal especially if they really love each other.