I hate when authors make stupid plot choices like this that just don’t make sense. you’ve established she’s super smart and has dealt with people all her TWO lives- there’s no way whatsoever she would make such a stupid decision like this IN ADDITION to not listening to the one person she trusts. this kinda shit pisses me off so bad it’s just such lousy and lazy writing
okay I’m confused now are they both her biological kids?
In what I understand - no. Taeha is bastard child (Mistress's child). The scumbag bro is chairman's and that woman's lawful son. I think that the father want everyone to treat Taeha as a real son of her and they are playing lovely family like that to not damage the image of the chairman.