User blog comment:Animegeek1689/Does Issei really love Rias?/@comment-219.74.133.187-20180501073415/@comment-28884330-20180504041424

Rias is the story's and the narration's number one, but Issei doesn't have one. That's the point of the harem, he will make all of them happy and love them equally. Not in the sense of lessening love on one so he can share it on another, but in that he won't lessen the affection for any of them and keep it at full constantly.