These people were in civilian clothes, off duty and conducting their life - I believe that this has f# all to do with the RN.
It's no different to other uniformed roles - consider the situation if all involved were serving Police officers - it'd be just as bad, if not worse.
As PS says, life in uniform is not the same as in a civilian job, and people should think carefully before a) joining and b) going out and getting totally ratted.
Corrected for spelling