The One With All The Kissing - S5-E2
Corrected entry: When Rachel is getting rid of her date to go inside and console a depressed Ross, you can see a crew member just as she opens the door when she goes back inside. That's neither Chandler nor Joey since Ross was just sitting there alone.
Correction: There is no-one else there, except Ross in the background. What you see is maybe his shirt, but nothing else.
Anastasios Anastasatos