The person on he road trip in charge of snacks
Ellen is the best snack captain, she packed subs for lunch, almonds, and ice tea.
The person in the relationship who thinks they’re the better snack buyer, but usually a person who uses this term selfishly is not.
I.E “I am the snack captain and pretzels are a good snack.”
Also
“You’re just mad you’re not the snack captain because you like candy.”