Originally Posted by
transformyself 
How do I say this to him? How do I say, "hey dumb a**, I"m not bailing you out, you have enough money to go to the bar, you should have freaking bought groceries instead!!'
"You are an adult. I have faith that you will be able to budget and buy the needed groceries."
End of statement. If he tries to engage, you have the choice not to.