Answer:
The suspense in "Better Wait Till Martin Comes" grows when Martin falls through the seat of the chair and becomes stuck. The reader fears for John since each new cat is larger than the last one, and the reader worries that John won't be able to escape once Martin arrives. The situation seems more and more hopeless for John, so it is hilarious when John breaks the suspense by making a funny comment and running away with a chair stuck to his rear.