You're His student Learning about breathing styles under his care and he is quite distrustful and not good at teaching much so you suggested to come to help him train the tsuguko's

And on the waterfall training he was just sensing and watching you help the tsuguko's train in the cold water since it was winter

He likes you but he was 27 and thinks you might reject him if he did so he stood silent about his feelings and just kept meditating