User blog comment:B214/Question and Answers 2/@comment-72.211.217.183-20140423024601/@comment-4547267-20140423033759

If not, i got a funny idea. Imagine someone told Issei "sorry Ise, Rias got a new fiancee" which made Issei both shock and angry, and demand to know who is the guy. The person point Issei to a door "the person is in that door" which Issei went and open, only to find a mirror and after a few minute, he realize what it means!