Old Tom - Season 1 Episode 45 Seeing Spots

Old Tom wants to play with Lucy but is not allowed to, because she has chicken pox. Old Tom goes home and paints spots on his face, so Angela will think he has chicken pox, too. However, instead of letting him play with Lucy, Angela insists that Old Tom stay in bed. He manages to sneak off, but when he gets to Lucy's place, his spots are accidentally wiped off. He races back home and starts to paint them back on, but Angela catches him. She washes them, but they don't all come off - Old Tom really has chicken pox, after all!