Many of you gus say that Tsunande is the trigger of jiraiya being a pervert.

Maybe that is true, Jiraiya is a pervert and he is proud of it and shows it. while Orochimaru is a closet pervert, and going for young kids especially boys and want to do stuffs with them. So Oro is like the creepy uncle, and Jiraiya is more of the open perverted father.
and guess what both of them have incommon? Tsunande.

I have a second theory about that.
All of them Jiraiya, Oro, and Tsunande had sandaime as there sensei.
And we all know that he was a pervert. so he may have raised those kids a bit wrong.
But the only person that came away was Tsunande, but who knows? She may also be a pervert.