Which episode is it that Chachi and Joanie go into the Cunningham's kitchen and it looks like they should be out of the scene, but you can see them flirting? I believe it's an episode before Joanie and Chachi were dating.

I found it. It's ep 5.11 Bye Bye Blackball at about 7 & 1/2 minutes in where Marion is telling a story and J&Ch take the groceries into the kitchen but you can still see J&Ch joking and laughing