User blog comment:Animegeek1689/Does Issei really love Rias?/@comment-23853100-20180504100138/@comment-99.194.133.69-20180806013849

Here is what would satisfy me. Whenever any of the other girls try to do anything sexual with Issei, he doesn't go through with it. And the reason for that can't be because they caught or interrupted by something or someone. He doesn't go through with it because he willingly chooses not to. He resists whatever temptation any of the girls try, willingly chooses not do anything with them, and tells them that, as much as he may want to do stuff with them, he refuses to do anything sexual with anyone until after he's had his first time with Rias.

That is what would satisfy me. If Issei starts doing that in the light novels, then any doubts that I have regarding Rias' place in Issei's heart will completely vanish.