Why Are All the Fairies So Obsessed with My Downfall?

Lin Que had a dao companion, Qin Wanyuan, who loved him with all her heart. He thought life would continue on in quiet, simple happiness just like that.
But one day, three letters appeared on his desk.
He opened the first one.
It was from his former senior sister who was a cold, yandere-like woman who had once imprisoned him and left deep psychological scars.
“Don’t worry, Wanyuan won’t find out.”
He opened the second.
It was from his dao companion’s master, the dignified woman he also respectfully called “Master”. But her words revealed a shocking side of her:
“Que’er, you wouldn’t want your dao companion to lose her status as a direct disciple… would you?”
The most disastrous was the third letter written by his sharp-tongued sister-in-law.
“If you don’t want my sister to find out about all this, come to my room at midnight…”
All he ever wanted was a peaceful life with his dao companion.
So why have things turned out like this?