Whose decision is it that George needs a hobby? I would say it is Lynne's as she is constantly seeing him lazing around the garden with a short drink. It's obviously not gardening that he wants to do so I suppose Lynne has given him some sort of ultimatum; get a hobby or do the gardening. For some reason George can't come up with a hobby himself. What were his previous ideas? Speedway? Parkour?
George, whose jaundice is subsiding, was so excited about the idea of art that he bought one of those special tables and lights that designers use. Now it's being used for something as dull as stamp collecting. He's obviously not excited about philately, however after a very short period he has amounted a generous collection. Perhaps he stopped off at the post office for a couple of limited edition display packs to get him going.
So what is body painting? It could be just painting pictures of bodies but isn't that called life class? It's without doubt that this woman will be nude in this class, but body painting sounds like that the students will be putting paint on bodies. Whether she shows them how it's done on her and then the students paint themselves or they just put paint on her body is still undecided. Either way Lynne is right to stop it but she could have thought of something a bit more adventurous. Cliff diving? Snake wrestling?