Originally Posted by Sykes

But if the rules aren't enforced, first class passengers might be forced to mix it up with the hoi polloi. Perish the thought!

95% of the time when I see a Y passenger use the F lav, it's because there's drink service happening in the main cabin of a narrowbody aircraft and it's a giant pain to try to get by. Many of those times, I've seen the FA doing the drink service point the passenger to the F lav. As long as it's not creating a backup in the F lav, I don't really care when I'm in F.