How would you feel about someone making silly faces with your child?

Say you are in line at the grocery store and your child seems particularly interested in the person behind you. They are kid-friendly and make funny faces to amuse your child. Would this bother you? Would you have any concerns?

I will be upfront and say I do this often with children when they stare at me. Most parents could care less or seem to find it amusing. However there is always one or two who seem to think it is awful and thus I stop as it is their child (but the damage has already been done as their kid has just learned a new face to make and often keeps making it even as the parent wheels them out of line). The parents who get concerned are the ones who give me pause about doing it. but i don’t think i’ll stop just the same