Not sure I understand the logic of not even trusting your wife.
He doesn’t tell his wife because he’s probably thinking “Loose Lips sink ships” If his wife tells just one person about their stash then everyone knows when SHTF comes. Friends, relatives,strangers, etc.
When things get really bad such as the communist created Volga famine and Ukrainian famine, the fewer people who suspect you may have something, the safer you will all be.
In these type situations, anti-hoarding laws will be in effect. If discovered by authorities, all in the household are classified as hoarders and are subject to summary execution. Don't think you can store provisions in the attic or in wall voids, all those food hiding tricks will be known and searched for.
When cannibalism sets in, desperate people do desperate things. If you don't want to have to use deadly force against your neighbor or best friend, don't give them any reason to suspect you have provisions.
For certain, if you are sent to the Gulag far from anywhere and at some point two inmates approach you about joining them in an escape, don't do it. After about two days outside of camp, their plan is to use you as food for the remainder of their journey.
Don't believe me? Read accounts of the Russian famines and the Gulags.