Based on the below prompt, by hybridfanfiction on tumblr: 

You decide it’s time for your son to have his first hybrid and take him to the nearest shelter. Surprisingly, he goes straight past the hybrids his age and goes to the adult hybrids area. You observe him as he talks to each of them, asking strange questions like, “Do you tell good bedtime stories?” or “Would you try to make me clean behind my ears?” After what seems like forever, he pulls a gorgeous hybrid towards you and asks, “Do you think my Mommy is pretty?” The hybrid blushes and says yes, which seems to please your son. His smile is blinding as he nods and tells you he’ll take this one. Despite your confusion over why he would want a grown hybrid, you agree because they both seemed so happy. Little did you know that your son had been looking for a dad, not a friend, and that he decided your new hybrid was perfect for the job. Eventually, you thought so too. 

I've just switched it from mother and son, to noona and dongseng. I've already written this story, and will post it on Christmas Eve.