Leaping far ahead....
On my way down to the crew rest I noticed a couple having sex in their window/aisle seat. Whilst not loud/vocal by any means they didnt realise that the blankets over their heads left them exposed below the waist from time to time.
It was a late night flight (4-5am'ish) and the only other people aware of the couples antics were 5-6 Chinese men quietly enjoying a beer and a show from their nearby seats.
In short no one was being offended.
I decided to stay as it was patently obvious the display was reaching its finale.
Only a few seconds later the young lady (on top) took a peek from her blanket and, unsurprisingly, was quite shocked to see a pilot only 2-3ft away (applauding slowly at the latest inflight entertainment!)
End result:
No one was offended, 2 randy Dutchies left slightly red faced.
My point is, its all about time and place. You cannot legislate for all situations. Commonsense needs to be applied by passengers and crew alike.
Bear in mind that Playboy, particularly the Black Edition is banned in many countries.