I don't think the dad's the trigger cause they sort of have a cold father and son relationship at best, it's the mom and her weird controlling ass that made him go back to his old self lol
It wasn't the Father, his mom triggered him, even Yu felt something's off when he met Taka's mom, and I think the trauma is related to SA or something cuz there are phenomenon where people who have sexual trauma can become hypersexual in response
how did his father trauma get him to wanna fuck him to his kinky af death wtf