Is it normal for a partner to send you Venmo requests for eating "their" groceries when you live together?

My boyfriend and I moved in together about 6 months ago. We split rent and utilities 50/50, but we buy our own groceries.

Occasionally, if I run out of something, I’ll use a splash of his milk or eat a slice of his cheese. I don't think much of it, but lately, he's been sending me literal Venmo requests for like $0.45 for "two slices of bread" or $1.20 for "half a Gatorade."

When I brought it up, he said it’s just about respecting boundaries and keeping finances perfectly fair. I feel like it's insanely petty, but he acts like I'm the one being entitled to his stuff. Is this a normal way couples handle groceries?