I remember a fic that had the "facts of life" explained to Ranma, only for
him to find himself suddenly start thinking about sex like a normal teenager.
Ranma believed he was becoming a worse pervert than Happosai thanks to Akane's conditioning about perversion.
I believe Cologne then explains to the fiance brigade that he had no idea what sex was and that thanks mostly to Akane, Ranma is now probably considering seppuku as he probably sees himself as worse than Happosai.
I don't remember this part exactly, I just recall that Cologne was explaining things to the fiance brigade and made a comment about Akane convincing Ranma sexual thoughts were all perverted.
It is NOT "newRanma" by C. Jones.
I believe it was a much shorter fic, probably a oneshot.