This is exactly like a boyfriend I had at uni. Came from a well off family, his parents paid all his bills and gave him a pretty generous amount for food and disposable spending. Yet you'd never know it, he was tight as
duck. He'd steal food from his housemates - and other peoples! - 'rescue' anything headed for the bin no matter how gross it was, and meals he bought for himself would be like plain rice and mince seasoned with salt and pepper. He wouldn't even spring an extra 50p or so for a jar of sauce from Lidl because it wasn't necessary.
Then it came to nights out, gadgets, the gym, and other tat and money was no object. He once told me he'd spent £45 on a fidget toy for example to 'help him concentrate'. I remember thinking you have money for stuff like that but eat like
tit .
I think what it boiled down to is food was his only necessary expense and he resented spending on it because it got in the way of his 'fun' money. He didn't care about taste or nutrition or enjoying his meals, he just wanted the lowest price tag possible. And he'd take food from people with less than he had just because he could.
Jack reminds me a lot of him actually. And yes I now can't believe I went out with him.