DH and I live with FIL and grand-FIL. We've been here for a year and I'm being driven crazy.
Yesterday evening, I bought double cream to make ice cream this weekend.
This morning, I noticed a third of the cream has disappeared.
When I picked it up at the supermarket, I took off the clean plastic lid to be sure the cover you peel off was still sealed, so it wouldn't have been a third empty when I picked it up.
The bag I carried it home in isn't messy from a leak (I would have noticed it unpacking yesterday, but I double checked just now).
We definitely didn't use it cooking yesterday.
I texted DH in case he added it to porridge or something at breakfast (even though he would know better). He said it wasn't him, but suggested maybe someone (FIL or grand-FIL) thought it was yogurt.
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I'll still make a smaller batch of ice cream, but it's just annoying.
I've moved it to the back corner of the fridge that (I think) is clearly ours so no one else takes more. I don't plan on saying anything, but I might be a bit passive aggressive and put a piece of tape across the lid in the future so if someone does try and use it, they'll see it's mine.