There is an idiomatic expression: lInchuq "share each other."

This is not a euphemism, but Maltz admitted it's a little risqué. lInchuq ("they share each other") means that they (whoever is being talked about) have a physical relationship of some sort. The phrase is general - it doesn't imply anything about exactly what they do physically. It also doesn't necessarily mean that they are doing something right now (at the time of speaking).

The relationship could be relatively light (a little nibbling) or heavier (really biting) or beyond (Maltz thought that Terrans might find that part a bit risqué).

As with other verbs with -chuq, the prefix has to indicate a plural subject and no object:

malInchuq
SulInchuq