Wife or concubine?

[7summits]

An architect, an artist and a climber discuss if it's better to have a wife or a concubine.

The architect: "I think it's best to have the long lasting relationship to my wife. It gives me the sort of peaceful life I need for my work."

The artist: "I think it's best to have the wild and passionate relationship to a concubine. It gives me the inspiration I need for my work."

The climber: "I think it's best to have a relationship to a wife and a concubine at the same time, and they should know about each other."

Surprised by that the others asked why.
The climber: "If you have both a wife and a concubine, then they think you spend your time with the other one if you are not there. So you have enough time for climbing."

(thanks again to Herbie)