A little girl got a lesson in playing nice with her baby brother, but only after she successfully played, well, not-so-nice.

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After covering her little bro from head to toe in diaper rash cream, the adorable 3-year-old gets caught - on camera, we might add - by her faux-angry mom, who tells her, "You are in huge trouble by the way. Like, super big huge trouble."

Not for nothing, the baby doesn't seem to mind the feel of the cream smothered all over his body, giggling for the camera at the situation.

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Watch the hilarious video below!