Phil, I realised that there is a parallel in Russian to that biblical sexual usage.
In biblical Russian we use resultative form of "to know", which means "to learn", "get to know", an act of transition form not knowing to knowing. Познать.
There is another verb (from a related root знак 'sign') - познакомиться. Means 'become acquinted, familiarize yourself with someone or something', 'get to know'.
And it is used often in the context of young people of opposite gender. A girl saying that she 'got to know a young man' implies that she's interested, a young man saying that he wants to get to know a girl in a bus means she is pretty. "I got to know Mary" or "got to know a person..." don't imply anything like that.
And the dumbest Russian pick-up line ever is "girl, may I get to know you?" "no". The answer "no" is almost a reflex, girls first say "no" then think. Which makes sense, because it's dumb. It is half-way towards developing a new meaning. And it makes me feel a bit weird, because it's whole new notion. (maybe that's why such a reflectory reaction). I mean, normally to get aquainted with someone I just say "hello, I'm Kostya" and now we are aquainted. You can't say you know someone, but don't know her yet, because you're not sure if she is ready to know you, but you know each other anyway. Knowign is not voluntary. But in the pick-up line it comes with "may", it is something the girl may or may not agree upon.