User blog comment:B214/Light Novel Volume 16 spoilers/@comment-9339850-20131031065534/@comment-1392308-20131103031912

Seems like Asia, Xenovia, and Irina are feeling the same way Rias felt in Rias in Wonderland. Issei really needs to manage his time with the other girls beter but it's understandable that it's difficult for him to do. lol, he even lampshaded that in Volume 14. Good thing Irina and Xenovia are getting focus after Rossweisse, they both need it.