looking for a good kdrama/jdrama where husband or wife has a secret child
or a drama where mother or father is getting out of jail and seeing there kid after so long
✔️ Old Boy (Chinese)
✔️ Oh the Mysterious ( 2 secret kids)
✔️ Moorim School
✔️ Mirror of the Witch
Hateful but once again
Probably not what you're looking for, but here are also some dramas where the female lead is reunited with a parent when she is a young adult after they were separated from them or assumed they abandoned them or died when she was a child:
not really with the leads being a married couple...f but still one of the leads realize or find out they have a child belatedly...
Let me Introduce Her | currently ongoing.