every comment i come across keeps referring to Dangerous Liaisons or Les Liaisons dangereuses book by Pierre Choderlos de Laclos, which as been a while since i've seen/read so remember the plot vaguely.

the korean take is interesting, more f*cked-up as they r family not ex-lovers who r bored and a bit narcissistic - who for the fun of it make bets about seducing people. making them family has its yuck factor for me, and both of them were equally messed-up, doing anything for the fun of it. treating others like pawns for their amusement, which given the time period was befitting, as usually rich people didn't have many ways to entertain themselves - so a twisted mind "helped".

didn't by the love story, not between the cousins, neither the young lovers who just exchanged letters, or the widow and Jo Won. that was kind of a hard-sell and left me feeling it was either rushed or lost in translation.
don't find this better, just different, even the sex/nude scenes weren't overly R-rated, yeah it was needed to tell the story, but as opposed to other movies i've seen, it was moderate. not vulgar.

still good, not a rewatch, but interesting (as someone who has seen other adaptations of this movie from other countries, quite good).