After their last conversation, Orochimaru and Karn rarely met.
Their intentions were more or less confirmed, and they could cooperate more deeply. As long as Orochimaru became the Fourth Hokage, Karn's relationship with Konoha would ease considerably. Orochimaru would also shield Karn from Konoha's obstruction and help him seize the Daimyo's position.
Each had his own wants and needs. Orochimaru's bottom line was simple; as long as it was not crossed and there was a need to cooperate, he was very easy to talk to.
The current Orochimaru was unlike the man he would become over a decade later, after losing his disciple and the Hokage Position. Back then, he would have nothing but his title as one of the Sannin, with little left to care about in the village, and only after seeing through the nature of life would he choose to develop forbidden techniques and defect.
Now, Orochimaru had a disciple with a bright future, was himself a renowned ninja in the shinobi world, and had just commanded the fighting on the Land of Grass's border. His prospects were limitless.
He had no thoughts of defecting at all. His current ambition had merely changed slightly under Karn's influence, from learning every technique in the shinobi world to mastering all knowledge.
However, his status as a Konoha jonin and his title as one of the Sannin did nothing to help him achieve his dream, so Karn had greatly amplified Orochimaru's desire to become Hokage.
And Karn could provide him with more resources. Their goals aligned, though there were some differences. Working with Karn was far better than spending every day guarding against that foolish Daimyo of Konoha.
For these reasons, the relationship between Orochimaru and Karn had grown closer.
He had also disclosed a few things about White Fang