User blog comment:B214/Volume 17 spoilers./@comment-82.48.169.148-20140220135026/@comment-1359322-20140220153841

THat's still fine since Issei actually wants to have many girls except he's focusing on Rias only right now. Issei's greatest failure is the fact that he just can't understand how the girls feel, he constantly think that they are doing it for fun and not because they love him. Then even after the girls express their feelings to him, Issei still doubts and hesitates about how he feels towards them, due to his uncertainty on how the girls feels about him.