1) John is a gardener, and of course Rodney doesn't need one, because he only has a balcony he never uses (too much sun). But with Jeannie pregnant again, suddenly Rodney is responsible for Jeannie's garden: lawn mowing, hand-weeding, and other horrible things. John is the solution to (all) his problems.

2. Historical AU: In ancient Rome John buys a slave (Rodney) for doing the administrative work on his latifundium. Rodney not only revolutionzes the farm work but also changes John's view of the world.