something happened in the past..?

[MegzZ]

While I was going through the itachi pursuit mission arc in the manga I saw a page in which
Suigetstu says to Karin: I really know in the past with sasuke you know..
After hearing that sasuke only said: suigetstu stop messing with Karin
Though I still think sarada is sakura's daughter
But you never know what can happen

 

[Rikodou Mode]

It's obvious he's had se with Karin a few times before she was ever introduced in the manga, you can tell by how persistent her thirst is

 

[Kirokill]

Kishi trying to not put the manga under the M flag.

 

[Torche]

Didn't Sasuke save her from a bear in the Chunin Exams? Or was that anime-only? Can't remember, tbh.

Edit: Don't even know if this is what you're trying to ask/say, tbh... :|

 

[MegzZ]

If there wasn't anything she wouldn't have gotten close to him on their first meeting

 

[Kingu]

Them having *** was part of Orochimaru's experiments, to create the perfect being. :bdpf:

 

[Kaneki Kun]

Them having *** was part of Orochimaru's experiments, to create the perfect being. :bdpf:

Lmfaoooooo!

 

[ANiMUS]

I think the translation I read that scene said that Karin did something to Sasuke, but whatevs. Anyway I doubt there is any truth to your assumption seeing how Karin tried to shut suigetsu up before he said something that Karin did not want Sasuke to hear.
When Sasuke saw them acting out he blamed suigetsu and told him to stop.