Well there's 4 of you there full-time and your DH is only 1 of the 4.  His child only stays there about 4 days per month.  As such, he and his child is only a small percentage of the food consumed in the household.

I really do see his point tbh.  You and your 2 consume the most by far.  Plus, you get CS to help cover those sort of costs.  It is a logical request. 

How do you split utilities and rent? Maybe something along the same lines as that? If you don’t want to be constantly dividing bills you could agree an amount (not necessarily an equal amount) to each contribute to a joint account each paycheck then use that account to pay for rent, utilities, food and other household items.

If you moved in together recently then you could always compare what you used to spend with just you and your kids on groceries and what your husband spent on himself and then use that as a starting point to deciding a fair split of the costs now. 

If you keep finances separate then splitting costs according to number of kids and time they are with you seems reasonable. If you want your husband to pay towards your kids would you be happy to contribute towards the child support he presumably pays his ex? 

Maybe it is time to sit down and go over all things finances with your husband so that you have everything on the table and both agree how to set things up between you. If this is a new thing he is suggesting there may be a larger underlying issue at play that is bothering him apart from the groceries.

You've been together for 6 years, how have you handled it previously? 

Or have you now recently married and moved in and were previously dating but living apart?

Sounds like your DH wants to keep things financially separate when it comes to the kids so your going to need to have a sit down and work it all out 

I agree you should be paying a higher percentage, but I’m not sure why your DH thinks your ex should have to foot the bill for groceries in your house? Unless he means you pay 1/3 from your salary & 1/3 from CS? 

If you have separate finances, his request doesn't seem unfair. Now, if your kids are very young and don't eat much, or if he and his EOWE kid eat a lot more/more expensive food, or if there's a large income disparity, or you do a lot more of the household work than he does, etc., you may want to rethink the percentages. In theory, though, it seems fair if finances are separate. Out of curiosity, why is this first coming up after 6 years?

I love the idea that your ex has to pay for the kids' food, not you, lol. As if only fathers are responsible for paying for their kids' expenses.

Anyway, seems fair to split it 2/3 you and 1/3 him, unless there is some other factor you aren't sharing - like he makes 10x what you do. I'd be annoyed if he was splitting hairs in that case, too. Lots of people on here are bothered by the expectation that they should pay for their stepkids' expenses, so it's understandable that your SO might feel that way.

I never quibbled over the grocery bill but my SS wasn't here a ton and he didn't eat a lot.

Should have discussed it before you hit the check-out line, though. How people manage money is a huge factor in breaking up marriages.

Who is paying for housing?  By ex paying, does he mean it should come from child support?  Is ex paying child support?   I can see frustration if you think that the child support should all be used for extras, and none for food and housing. 

I think you two have a lot to talk about before going grocery shopping again.

Does your ex pay CS? If not, why? Unless he is dead, he should be paying, or an order should be in place so that you at least get some money around tax time.

Do you have separate finances? How are they separated? If they aren't separate, does your new DH feel like he is unevenly contributing to your kids while he feels like he is on a budget for his own? 

He is feeling something and you need to figure out what that something is and find a compromise. No, it's not fair for him to contribute to your kids in a 50/50 fashion unless you're also contributing to his (which would include CS) in the same way. At the same time, if you're contributing to a larger portion of household expenses because his CS is outrageous, then I could see where you'd be offended since you're having to support him.

Ultimately, it doesn't matter what the reason is, you all need to talk it out. He's not happy with something, and you're upset by his response to whatever upset him. Hash it out now before it festers, but recognize that his feelings are just as valid as yours and you'll both have to come to a compromise.

Just adding my two cents to your question.  For me, it was simple.  I married her and not her ex.  We share all the expenses and since I'm taking her and her sons, it was a no brainer; 50/50 between us.  Maybe I'm old school just can't see yours/mine it's ours or nothing

I have 3 kids, dh has 1. Mine are teenagers, his is 6.

Amount of food wise, my 3 and dh are the biggest eaters. Constant face stuffing.

I have a grocery budget and I stick with it. If they want extra they can get it themselves... and if they require somethi g special the parent gets it. (Ss has juice boxes and special peanut free snacks that are pricier than the ones I regularly buy...oh well....... dh buys those)

Whenever dh and I talk money, it always comes down to "yours and mine" and it gets so irritating... because I get a few hundred b7cks a long from the government for them each month, representing 50% of the total amount they're entitled to.... yet so does BM. Except she gets the whole 100% rather than 50%. Meaning the 50% for our household comes from my budget.

Dh argues that it doesn't cost that much because he's only 6... oh great, dh, then if it's so little BM shouldn't mind sending that money over.

We are 6. Realistically, amount of food wise, ss and I are about even... and dh is even with any of my teens.

So... I don't stress about it but I do keep track in my head... I "arrange" it so that when there's few of ss's stuff left I text dh to pick some up on the way...... I guess you could say I manipulate him into paying for his own stuff...Lol

He's not wrong in a sense... he's really saying he's asking you to pay a more fair share of the bill since you and yours use more of it than him and his.

It's not an unfair request.

Make it basic... the house bill costs 50 regardless of who uses it or for how long. It costs 50 if it's full...if it's empty... it's 50. Therefore you 25, him 25. Fair.

Food bill costs 1 per person per day. His is 30 days for him, 4 days for his son. 34 actual cost for dh and son. You is 30, your kids are 30 each... so 90 for you three.

34 and 90 = 124$.... being split in 2. 62$ each...you're paying 28$ less than your share of 90$...and dh is paying 28$ more than his share if 34$. 

Hes just asking you to pay your own 28$ and not stick it on him....even suggesting that maybe their father should be responsible for the difference rather than him.

Does it make more sense explained that way?

You all really should have discussed finances before getting married.

I can understand his frustration. His child is on the home 4 days a month.  Yours are there full time.  What you are  contributing towards the support of his kid, (food and utilities 4 days a month) is nothing compared to what he is contributing towards yours(mortgage year round).

Your kids are benefiting the most from the household expenses that the two of you are paying. 

If your ex is paying less CS than what he would pay is the you went through the courts, then he is also benefiting from what your husband is paying.

Even if they are paying the same amount each month, the children are not benefiting equally.

I have no kids, DH has two. We split household costs pretty much 50/50. However, there was a time in which I somehow ended up spending hundreds, hundreds more in groceries for some months before I realized why I was broke at the end of each month and he was off playing...hard stop.

I agree to pay half groceries (esp now that OSD is not in the picture) for the basics. Anything special then he pays. If I end up doing more shopping on my own, he pays a higher percentage. It works well and we both agree to it. Basically you have to discuss it.