If he isn't on the same page as you then your plan has no hopes of succeeding.
My sister is the same way. Her husband makes a good living, he's an engineer of some sort. She made, clear, over $10K last year on her Etsy shop. She also is older so she gets social security each month, he's in his 50's and younger than her.
So they make a really good amount of money each month. They live in a beautiful huge house with a pool and manicured lawn, it's in a super nice neighborhood too.
My sister is constantly on him for anything he spends any money on. He's a Southern Baptist and she's a Jehovah's Witness. Every dime he spends on tithes and additional offerings or building funds or the Lottie Moon fund....she's gripping at him again.
I tell her over and over and over when she calls me to talk about how he gave his church hundreds of dollars this Sunday. She needs to take care of her own money and let him spend his money how he wants it.
She's a real penny pincher and he's a not a total wild spender but she doesn't want him to spend money the way he wants to spend it.
I think that they need to keep their finances completely separate. That way she has no idea where his money is going. As long as the payments are made on the house, vehicle he drives, she pays her own car payment, and any other bills are paid then the extra money should be decided of course and certain funds set aside for savings or retirement situations but after than he should be able to use his money for stuff he wants.
The same for you guys. If your bills are paid then you guys must come to an agreement about the money.
I think you do not have half the bills, that's roommates and not a marriage. You both owe 100% of the bills. You both owe 100% of the house payments and every bill. BUT there is a line where you don't get to tell him what he can eat or not eat when he's at work.
If he is in a position where he is expected to go to lunch with customers or co-workers where they even discuss one point regarding work then you need to keep track of those "out of the office meetings" and file them with your taxes.
He needs to eat lunch out if he would be looked down upon by anyone in the office. They'll think he's poor and lose respect for him, he may end up losing out on promotions or better clients or even higher paying jobs.
It's not about him minding you or doing what he wants. He's in a position where he should be able to eat if he's hungry and not have to take him lunch.
I suggest you keep your coffee club, that's an amazing group. Keep eating your lunch like this IF, IF, IF you enjoy it and find it perfect for you.
BUT if YOU would really love to go out to eat with some friends with work every now and then or eat a delivered meal to the office then do it.
If you can find a way to set a goal and do something where you can totally be on the same page about the money you want to save that's when you can set a goal and find fun ways to meet the goal.