In the episode "The big sprain", Alice sprains her ankle and the kids have to take over the cooking and other house duties. One morning, Marcia and Jan are mad at each other about doing all the work, and Jan exclaims,"I'm not washing all these dishes, I will be here the rest of my life!" That was in one scene. In another later scene, Carol, who is taking care of their aunt, calls and Mike is in the kitchen with the kids making dinner. As soon as he picks up the phone, the kids start arguing and making all this commotion. But listen closely to the background while Mike is on the phone. You can hear Jan saying the same thing over and over and over again, the same thing that she said earlier about the dishes. I guess they just decided to replay their arguing over and over again, thinking nobody would notice. Slip up!