User blog comment:TheBlueSlug/Ending/@comment-24098614-20141115011727/@comment-1359322-20141115013402

Rias isn't selfish in nature, she loves all her servants equally, it's just that she becomes overprotective when it comes to Issei and refused to share with others. If Rias was truly selfish in nature, she could have just use her authority to prevent the girls from sleeping in Issei's room. Plus during the start, Rias had no clear answer if Issei will agree to be her bf and husband, so she becomes quite monopolistic, but even so, Rias has never done anything selfish. She just tends to argue with the girls (mainly Akeno).