I think so too but isn’t he the one who cheated when they dated when they were younger? Mashi
It wasn't him. He loved Mame from the begining but never acted on it since he knew about her feelings for his brother Sou. It was their friend Kyoichi who is now a priest who dated her when she got rejected (again) and then cheated on her.
SHIT IS SO GONNA GET REAL MWAHAHAHA