wait im confused what does them meeting up and doing this have to do with saving the twink...

the seme has made a deal fhat once nanjo ssi the uke sleeps with him the seme will stop seeing the evil twink

nanjo wants mokhyeon to leave seonwha alone not knowing their history fr and wants to protect seonwha from all that (but is being weird+stubborn about it) and mokhyeon says the only way for him to stop is if he does it with nanjo... now we're here and we'll see how this plays out :')

it's actually ridic and seonwha really doesn't need to be there ╮(￣▽￣)╭