User blog comment:B214/Volume 17 spoilers./@comment-117.193.172.96-20140220062652/@comment-117.193.172.96-20140220072623

Not exchanging pieces with rias would be more profitable according to me. I mean he'd still be part of rias's peerage and have the girls there for himself if he marries her. Plus if he recieves his own pieces he could make another harem using it. :D