Crossed Boundaries.
Sometimes grandparents do something you’re genuinely not comfortable with like giving your child a formula bottle when they’re exclusively breastfed, a pacifier when you were not going to introduce one, or when they engage in risky behavior that was more normal in their generation like taking little rides in grandma’s arms in the backseat of the car with no infant seat. It’s best to address these infractions clearly, calmly, and firmly.