On the 10th episode that aired on the 14th, Lee Jung Shin (Sung Jae) had a scene where his mother (Kim Hye Ok) was upset at his older brother (Lee Sang Yoon).

Lee Jung Shin saw his mother's disappointment and kneeled before her and told her "Mother, I'm still here for you. Until the day you die, you are always my number one. I will introduce my girlfriend to you first, if you don't like her, I will break up with her on the spot"

But his mother was still upset and told him not to lie to her, to which he responded with tears in his eyes "I will probably not find a girl that I will love as much as I love you mother"

This further proves that Lee Jungshin has successfully become an actor.

You can watch "My Daughter Seo Young", every Saturday and Sunday at 19:55 (KST) on KBS2