User blog comment:Mejiaj1/Top 10 perverts on Fairy Tail/@comment-5840892-20130611183528/@comment-5840892-20130614043420

Bimbo would be what I would use to describe any succubus, but you have a point.

As for my solution, if any and all options are available (in theory or pratice) I was going to suggest taking the tsundere sister (Haru) back in time and showing her said event. This however results in a paradox:

If you go back in time to fix a problem, then you would never have the problem causing you to go back in time and fix said problem to begin with.