I remembered this oneshot about a rich(?) playboy who's like sleeping around with girls. The father got worried about his son, then his attendant gangrape the son, saying it was to make him a 'female'. I'm pretty sure it got tagged gangrape, mindbreak, h, something like bitch training but I can't find it
I forgot to add this yaoi doujin to my list;;;; help me find the title anyone
