Another vote for 'mind your own business'. If you did not feel the need (or had the guts) to address them immediately and directly you should not do it now.
All those who find sex disgusting and outrageous: get some!
I have been in the loo with girlfriends and on the one occassion with a very charming KL FA. Besides it being a very uncomfortable environment for sex and the near impossibility to get out without being noticed (especially on KL where they have no F) it is plane fun (yes, pun intended).
Of course she shouldn't have and the FA in this story shouldn't have but we are all human. So all those holier than though types here are first going to write a letter to their boss listing all the things they have done in the last 5 years that were against corporate policy.