User blog comment:B214/Question and Answers/@comment-121.219.254.24-20130215232914/@comment-33447191-20130216031812

Just my two cents (2¢) 

Issei has gone...somewhat far with some of the girls, to the point that it's just short of sex. If he will ever do so, it will probably be around the end of the series. I can't say for sure, but has there ever been a light novel in history that illustrated the details? There'll probably be many hints and suggestions to that area, basically to the point that it's just borderline, but there'll also be some kind of distraction or interruption that prevents it.