Spoilers:
As my first post on Yuri and Estelle, I just want to say that from the start of when they both met, Yuri found Estelle attractive but did not see her as beautiful till the tree healing scene of Halure. If you rewatch or replay the moment both Yuri and Estelle met vs. How Estelle healed the tree in Halure, it's clear that Yuri wanted to peek in on Estelle changing before Estelle grabbed her sword from outside the door, saying "flynn told me to be careful if I ever met you" and Yuri passively thanks Flynn for ruining his chances with getting with a noble but when Estelle miraculously healed the tree, the cutscene ended with Yuri staring at her in awe, as if he was just realizing that she wasn't attractive but incredibly beautiful and that there was something more than what he originally saw her as. From there on (and even before when you first meet karen and Richard from the traveling inn) there is heavy implications of Yuri and Estelle falling in love slowly with different gestures and how they are with each other in scenes and skits together. Even during the battle against Estelle, everyone had to make up their mind about killing Estelle, but when Yuri was able to bring her back, the cut scene with Estelle embracing Yuri is NOT something you would do to someone who is just a friend and her emotion in that scene is not an Expression you would give to someone who is not the person you love.
I'll touch more on this in different posts, but for now I leave this here
