If someone gave me a straw to eat cereal with and placed a spoon in my glass of milk I'd say there's been a

mix-up

noun informal

a confusion of one thing with another, or a misunderstanding or mistake that results in confusion.

"there's been a mix-up over the tickets"

synonyms: confusion, muddle, misunderstanding, mistake, error; informal screw-up

"there was some sort of mix-up in the birth records"

a combination of different things, especially one whose effect is inharmonious.

"a ghastly mix-up of furniture styles"

google

If someone gave me a straw in my cereal bowl and a spoon in my glass of milk I'd say there's been a

mix-up

noun informal

a confusion of one thing with another, or a misunderstanding or mistake that results in confusion.

"there's been a mix-up over the tickets"

synonyms: confusion, muddle, misunderstanding, mistake, error; informal screw-up

"there was some sort of mix-up in the birth records"

a combination of different things, especially one whose effect is inharmonious.

"a ghastly mix-up of furniture styles"

google