DH and I made the choice to move in with my parents for a little while in order to save for a deposit for a house (we live in a very expensive area, renting is more than what our mortgage would be!). We pay rent to my parents to live here and buy all our own food and toiletries.
My DB and his wife have recently got their first house and are in the process of buying things for it. Most of my things are in storage, but we have some items we took with us to our parents. Things kept disappearing and I've just found out my DM keeps offering them to DB and his wife and saying to keep them until we move back out. We have not been asked about any of this! DM has form for things like this and has been asked in the past not to (she'll offer friends of hers that DH or I will do things for them to help out but never ask us and then is cross if we're not free!)
I don't want to cause an arguement as I'm aware we are living in their home, but I'm really annoyed about this and don't know how to approach it without it being made into a big deal, but making sure she knows it's not acceptable.