A Christmas at Pasidian Palace — S.L. Morgan

It's been five years since the Guardians worked together to destroy the most dangerous enemy they had ever faced.
With peace in their lands, Levi and Reece have been living a life of serenity and peace, raising their three young children at Oxley Manor.
Everything seems perfect and well until Levi realizes something: a holiday he knows his wife as always loved on her home planet of Earth has never been celebrated in his realm. In fact, Reece hasn't had the privilege of enjoying her favorite holiday in over six years, and Levi vows to change that.
But can he? With his sister's wedding at hand, his own daughter professing her love for another as well, and wanting to have a new holiday introduced to Pemdas...Levi is determined to find a way to make all of this work no matter the sacrifices he must make.