That sounds difficult Rafals. They may have to learn the hard way.
I wouldn't tell them about your stash but keep a little bit for them. Eg an extra bag of pasta and a couple of tins.
Ex is refusing to stockpile. I think he thinks I am overreacting. I have stuff he could have that I bought before DD went veggie. But he can deal with going and getting stuff himself.
I have a bit in for a bin fairy neighbour who has helped out in the past quite a bit.
Depend of course on what you can afford and how much space you have as well as how close you are, and how rude they were to your warnings! Or is that just me?
On the plus side. I have just tried the salmon paste and it is bloody gorgeous.