Should adult kids living at home pay for food?

I have a 20-year-old stepson who lives with us. He’s studying and works part-time, so he has both student loans and a bit of income. Currently, he doesn’t contribute financially at home, but he eats a lot, and it’s always hot meals—he barely touches bread or cheaper options.

This is getting expensive, and I think it’s fair to ask him to chip in for groceries or start buying his own food. His dad disagrees, saying they have an agreement that he can live at home for free as long as he saves money in his housing savings account (BSU).

I’m not on board with this arrangement anymore, especially considering how much he’s eating. What’s your take—should grown kids living at home start covering some costs, or is it fair for him to live completely expense-free?