Why do so many Korean celebrities lie about being married and having children?

K-pop singer Lee Jae-hoon from Cool said he married in 2009 and has two children, two days after actor Sung Joon revealed his December 2018 marriage
Lee Jae-hoon of K-pop group Cool revealed on February 5 that he married his girlfriend in 2009 and has two children. It took 11 years for the singer to make the confession.
Lee told a local media outlet that he did not mean to conceal it, but had no place or chance to speak about his private life.

The revelation came only two days after actor Sung Joon delivered similar news. The actor, who is doing his compulsory military service, disclosed that he tied the knot with his “love of life” just before joining the army in December 2018 and has a child. He could not hold a wedding ceremony because of his impending military enlistment.
Both stars said they were cautious about going public since their wives are not celebrities and are unaccustomed to opening up about themselves.
But is there another reason for the concealment?
The stars’ fear of damaging their popularity could be a big reason, according to Kwon Young-chan, a comedian-turned-psychologist.

“Numerous celebrities believe that marriage will lead to a fall in their popularity”, Kwon told the Korea Times on Wednesday. “For them, losing popularity means losing fans who bring them economic gains.”