Me and DH have set a household budget as follows;
All household expenses including food are paid from the joint account. We totalled them up, set a budget including a buffer and then split it 60:40 with me paying 60 him paying 40, this was my suggestion as I earnore than he does.
I pay all child related expenses for my son, school dinners, bus fares, clubs, allowance, clothes, presents etc from my personal account because the children are mine from a previous marriage.
DD is 18 and buys all her own stuff and expenses and contributed £100 a month to food which goes into the joint account.
I have another DS who is away at uni and I pay anything for him out of my personal account.
Anyway all that to say, he is not subsidising my kids.
We set a food budget of £150 a week, if it the shopping goes over this then I transfer the extra from my personal account to the joint account. When DS was home over summer for example I was putting extra in every week which is fine. His GF also stayed for a week and I bout extra treats etc and feeding six People so it did go quite over but it didn't cost DH anything at all.
So this morning I am going to do the food shop since he is at work and he has just given me a lecture about not buying shite, trying to get under budget. Saying how when he went last week he only spent £120 (I was away with work for 3 days so he had less to feed) .
Would I be unreasonable to tell him to do his own shopping if he is that bothered!! It literally doesn't cost him a penny extra regardless of what I buy!!
(We are very comfortable financially so not like he is worried about money, take home between us of 6k and total bills including food less than 2k)