why can't we be happy ever

Unfortunately, Lan Zhan meets a tragic end He sacrifices himself to protect Wei Wuxian, his closest friend and love interest, from the evil forces that threaten to destroy their world. In a heart-wrenching scene, Lan Zhan slowly fades away as Wei Wuxian tries desperately to save him.
The child's birth caused a significant rift in the family, particularly with Lan Zhan's strict uncle, Lan QiRen. He disapproved of the relationship between Wei Wuxian and Lan Zhan, and the child only added fuel to the fire. However, their bond was so strong that even the disapproval of their family could not dissuade them from loving each other.

Lan zhan 2 months ago gave birth to his second child and he was happy that child looks so much to wei wuxian and have his golden eyes and he was super happy about it .

Mean while Wei wuxian was more happy because lan zhan gave him another son and he finally gonna have his own family .
But Lan xichen wasn't happy at all he knew everyone was planning to kill wei wuxian and he wasn't doing anythng to stop it he actually was participating in the plan he was gonna trick lan zhan to go away for awhile and then everyone would appear an kill wei wuxian .