Prepping depends on likely events and likely responses to the planned for event. Watching the "Loneliness , Depression and Hypervigilance" thread makes divorce or separation look like one of the likely events to plan for. I have not been down that road, but it appears to be messy, and appears that at least some of the supplies should be maintained offsite without the knowledge of wife/girlfriend/sidepiece.
Hoarding ammo from your teammates for yourself during a fire fight because what one of them *might* do is not a winning proposition.
With the prevalence of divorce and separation in our culture, especially in the professions that most hold in this forum, I understand the thought that “I need to keep something aside so the kids and I can survive if she or he splits.” However, that mindset makes you *more* vulnerable, not less. Keeping a relationship together is hard enough without maintaining secrets based in distrust. If the unthinkable happens and you are betrayed by a member of your own family, whether wife, child, parent, or sibling, what is going to save you will be what you invested in the rest of your family, not what you held back.
If you chose to be part of the team, you need to treat it like a team, if you really want to survive.