I just flew DUS-HKG yesterday and I can attest that a constant stream of PEY pax tried to use J lav. It was beyond annoying and dare I say ignorant from the PEY pax side. I was on 21A so I saw so many heads peeking through the curtain to see if the lav is free or not. There was a lady seated on 21D (I assume she's a Diamond because the ISM came to greet her, brought her bottled water,etc and they seemed to know each other very well whereas I was greeted by the SP) and she got so upset so she called the ISM and the SP and told them that they need to rectify this problem. ISM and SP then went to the PEY cabin and I saw them talking to PEY passengers seated on the first two rows and the stream of PEY pax going to J lav decreased dramatically. Except there was this one guy who was so stubborn and kept on trying to use J lav despite being turned away multiple times.