Beware this is NOT BDSM, like it was so soft I think some "vanilla" sex in some manhwa is racier than this
I didn't like the second couple AT ALL, started skipping their story in the beginning because they were annoying
Now for the main couple: I thought MC would be annoying but he ends up being the BEST AND BRAVEST like really he was so good, he acted stupid/bratty sometimes but he was the more mature one in this story. So why is this only three stars you ask? Well I'm very unsatisfied by the ending where the CUNT BIG BROTHER just ends up being forgiven by my baby Yi Seo because he's such an angel just by apologising and same for ML who did the "I'm breaking up with you for your own good because your bro said so", ended up hurting the MC so bad but was still forgiven so easily by my angel baby MC - so one star for the bad second couple and one star for the CUNT BROTHER and the too easily forgiven men of this story
How to Train a Good-for-Nothing Rich Boy