the way i see it, they have trust in each other and hyesung trusts seungchan enough that he knows he won't do something beyond their borders. when hyesung wanted to stop with their play, seungchan suggests something to see if he would like it. they're trying out something new so it's normal to feel indifferent or unpleasant about it, that's what most people feel when they try a new play during sex. they're in a perfectly healthy relationship ^^
the way i see it, they have trust in each other and hyesung trusts seungchan enough that he knows he won't do something beyond their borders. when hyesung wanted to stop with their play, seungchan suggests something to see if he would like it. they're trying out something new so it's normal to feel indifferent or unpleasant about it, that's what most people feel when they try a new play during sex. they're in a perfectly healthy relationship ^^