Responses

So Han Seori is the result of her mom drugging and raping Yeryeons dad. So after she was born, grandpa put her in an orohanage to get adopted out. But because he felt guilty leaving her there, he picked up Yebin, a random baby who's the same age as Seori, for them to raise instead (also so no one would talk about a secret child). Then Yeryeon was born after.
Can someone please explain yebins existence like my bird brain can't remember how he ended up in the family
( ・3・)