First Choice (2024)

Both couples break up due to misunderstandings and the ML wrongly believing the FL lied to him and used him. They reunite years later with the ML discovering the FL was pregnant when they broke up and he now has a young child with a health condition. Both MLs at one point move into the FL's home uninvited. There is a SML who has been taking care of the FL and the child and who loves her, but she only sees him as a friend.

Both are short length dramas in which a couple breaks up, only to reunite years later at which point the ML discovers he has a young daughter. Both MLs have a disapproving mother who tries to force them apart.