User blog comment:B214/Volume 23 discussion blog/@comment-183.87.180.246-20170602072629/@comment-30924344-20170602115426

Because this is a harem series. Multiple girls not doing that would be very strange and so what if he wasn't aware of other girl's feelings or was. Fact of the matter is, the main female protagonist of a harem series is always the girl who is No.1 and the other girls not being his gf's this entire time was my comparison to show the fact Rias is No.1. Even if all the girls and future girls loved him and he loved them since V1 but he still fell in love with Rias first, she would still be No.1. That's why I said she is No.1 but he loves the other girls equally. He realised their feelings half way into 4th arc pretty much and never made any his gf because all he saw was his Rias just being his gf. Rias is No.1 for everything. None of the other girls are even considered to be competition for his legal wife which further proves their relationship is No.1.