If things are that tight then YABU to go out and spend that kind of money on yourself in a fit of revenge - you'd be cutting off your nose to spite your face.
However, he is being an idiot.
If you are cutting right down, you do need to budget in something for entertainment - six months is too long to go without treats - even if it is only £10 per month.
Does he have his own bank account? Give yourselves an entertainment / treats budget each month and put his in his account (making him 'pay back' at least some of the money he spends tonight) and yours in yours. If he can't be trusted not to top it up out of joint money, take access to the joint accounts away. His money is then his to do as he wishes with and yours is yours and the bills still get paid.
Don't spend another lot of money just to spite him, you'll feel awful about it afterwards and will have lost the moral high ground in addition to wasting your previous attempts to save money. To recover the shirt and drinking money serve your H smart price beans on smart price bread until you've saved enough on his food to make up for the drinking money. When he complains or asks why he's eating differently to you and the kids just explain that his drinking money had to come from somewhere and you're sure he'd rather the kids diets didn't suffer just because he couldn't stick to the budget you'd both agreed.
It's so frustrating not to have enough money to socialise AT ALL, and as much as I completely sympathise with you - he should NOT be out pissing that amount of money up the wall - I can also understand his "rebellion"
I have a friend and her partner is so bad at saving that she has his account details and on pay day transfers the same amount from both of their accounts into the savings one before he has a chance to touch it. I was quite [shocked] when I first heard about this - thought she was mollycoddling him and he was an adult and had a right to spend his wages his way etc. However, now they are expecting their first kid and he has admitted on so many occasions how proud he is to have a healthy savings account for the child to draw on later. If it was the other way around, what would he do? If the answer is nothing then it is unfortunately up to you to get what you need done to support your family. I'd see about whether he'd let you give him a budget as my friend has done. They soon get used to it, after a few months of it