When it comes to "기러기 아빠", it' s mainly about a dad whose whole family but him gone abroad for his sons or daughters to study. He still remains in his country to wire some money for them or do anything to support them. He's a quite lonely man... Then "딸딸이 아빠". It refers to a dad who gave birth to two daughters(not ANY SONS!!!) in a row. Let's just say a dad who has two daughters. Hope this makes sense to you. For further questions, please be my quest. Thank you for your interest in our language.