I wonder how that slipped through 60's censors to begin with. They could have just extracted the material they needed.
They made it point to use the word "mate".
The fact that they're in Kirk's quarters where they showed his bed makes it very suggestive.
Kirk is shown basically giving in and they share a passionate kiss (they're both standing). When they return to the scene afterwards, Kirk is sitting
on the bed pulling up his boots, and gives like an exasperated sigh he just did something
. Deela is brushing her hair-again. Wayyyy too suggestive.
The funny thing, is Voyager did the lame continuity thing also. Janeway and Paris actually did it and had children --reptile salmander children.
Never mentioned it again.