George and Lynne are on a rollercoaster. George tells Lynne that Uncle Bob is terrified of rollercoasters. Lynne sympathises. George continues by telling Lynne that Uncle Bob said he'd only go on one if it has parachutes. Lynne thinks this is a silly idea and says that ejection seats would be much better. George agrees and is scared by the rollercoaster.
It looks like George and Lynne have taken a trip down to Thorpe Park as Chessington is yet to turn from a zoo into a theme park. Thorpe Park itself wasn't that great in the 1980s, what with only Space Station Zero and Phantom Phantasia being the good rides. This may not be anywhere in England. It now seems they have gone abroad, perhaps Florida. This would explain why George is only wearing a t-shirt.
George tells Lynne of Uncle Bob's phobia. It is not clear just whose uncle Uncle Bob is. As George doesn't use the term 'my uncle', Uncle Bob might be one of those uncles who was a friend of his father's rather than his brother. Lynne has met him too and he is now just referred to as 'Uncle Bob'.
Lynne is right, it would be a silly idea to go on a rollercoaster with parachutes. Uncle Bob was probably getting at that if he had a parachute, he could jump off at any time. Lynne thinks that ejection seats, she means ejector seats, would be better, but this is as equally a silly idea. Ejector seats without parachutes would mean that after being fired into the air, she would plummet to her death. If she combined her idea with Uncle Bob's, she might have a better solution, but to go on a ride which fires you into the air and then made you pull a parachute is far more terrifying than just a normal rollercoaster.