Tonight (January 3rd) we went to Diesel Diner for dinner. Before ordering, I went to the toilet upstairs. There was nobody inside when I walked in. As I was inside one of the two cubicles, I heard someone coming in. I thought nothing of it until I saw a hand and male face looking up at me from underneath. I screamed and the coward immediately ran away. I went downstairs to tell one of the waiters who was a female but she couldn't look more uninterested. I was appalled by this and the food was actually terrible. The owner later came in to tell that we can see the CCTV but have to come back the next morning. We left disgusted with the food and incident.