To lock up all our food etc when we leave

I wouldnt leave stuff for them but don't tell your dh or the rest of the family that you've done it deliberately. How much attention does he pay to how much olive oil or dishwasher tabs are left?

I wouldnt faff around with a lockabke suitacase, just take all the stuff you haven't used back with you and say "yeah we used up all the loo roll ourselves, were down to the last few sheets on the morning we left - squeaky bum time, literally, haha!" Or if they ask "didn't you leave any dishwasher tabs?" just say "not sure - we don't exactly count them, if there weren't any left we must have finished them."
Or the alternative, dh asks "sis says she couldn't find any laundry powder" say "yeah we only did one load so there was a full bag left so I just bought it back for us to use as we've nearly run out at home."

There can't be that much stuff that you need to always be remembering to take if you only go once or twice a year anyway. Just bring everything home with you and use it up yourselves rather than having special cottage only versions. Then when you go next time just bring your own stuff and then unless it is literally the dregs of some olive oil or whatever that would be more hassle to bring back, take it all home.

You already have to pack clothes, food, toys, etc new each time, adding some loo roll, laundry powder etc doesn't make a difference

Basically stop treating it as a shared resource that you all chip in for consumables as well as the place itself (because the others aren't doing the same) and just do as you would if you were renting it for a week privately.

I would hazard a guess they are already taking leftover stuff home. Including what OP has left behind. Otherwise, there is no way they could judge it perfectly to always have used up everything that has been left for them to that level of accuracy, consistently.

Do it gradually.
Leave 50% of what u normally do
Then 25% visit after
Then 10%..
Slowly does it.

I'd have washed them up by hand rather than let her have that little victory.

We have mentioned it before (see her 'we don't use much) response. Oh but I've just remembered, once when there was a day's overlap, DH suggested SIL pick up some dishwasher tabs when she popped to the village there, she conveniently forgot and we had to go out later in the car and replenish them for our last night's stay - meaning we only used one! They're shameless!

You know that if they turn up and there's nothing there, they will buy what they need and take it home with them, don't you? You have to treat them as they treat you.

You are not a good person. You should always assume the next person arrives late or exhausted. Them being able to have a cup of tea. When they arrive at your destination is a bare minimum.

Question - is two teabags left in the caddy more pointed than none at all?

I wonder if sil is jealous and doesn’t like that you own the majority and make the decisions. There’s obviously a big gap in finances which also could lead to resentment and disharmony.

id do whatever you can to reduce how much resentment you feel about the situation as dh doesn’t want the conversations.

You know that if they turn up and there's nothing there, they will buy what they need and take it home with them, don't you? You have to treat them as they treat you.

Ok ive just put a box of teabags and some olive oil in the suitcase that I know we won't get round to using, just to see how it 'feels'.

The combination is currently DS2's bday( but given she never sends him a card or present, I'd say she won't guess ). Still I should probably figure out how to change it.

We share a holiday cottage with DH family (his parents, older sister and partner) and use it at different times. For clarity- everyone contributes financially but DH and I the most as we are a family of four and earn more also.

In the summer holidays, we tend to go up the first few weeks of august, then head home. At this point, SIL and partner will come and use it. They probably use it more than us in total as they have no kids so can go during term time also, and can WFH so tend to have lots of mini breaks throughout the year.

When we leave, we make sure place is spotless and leave fresh milk (if SIL due to arrive), eggs, coffee, occasionally some treats and always whatever is left of all purchases (cooking oil, laundry powder, condiments, kitchen roll, plentiful loo roll).

On the flip side, SIL and partner will use all our stuff up and not replace it, meaning we often arrive late evening and find we are missing eg oil to cook dinner or even toilet roll.

We have mentioned this politely a few times but got no meaningful response (other than to say ‘it’s just the two of us, we hardly use anything’) This 100 per cent won’t be just thoughtlessness on their part - SIL is notoriously tight.

Anyway- we are due to pack up Sunday and I am considering putting all store cupboard items in a combination lockable suitcase and keeping them stashed away until our return. They will no doubt notice this as they take for granted things like salt and dishwasher tabs being available.

DH told me not to he so petty and ‘go high’, but honestly I’m fed up of SIL and her partner’s behaviour and this might be the only way to make them see what they are doing (although to he perfectly honest, I will slightly enjoy pissing them off).

So who’s right MN?